Friday

August 28, 2015
Total # Posts: 33,111

**Biology**

How is a protein different from a complex carbohydrate? a.The monomers that make up a protein vary whereas the monomers that make up a complex carbohydrate are all the same. b.Proteins function as energy storage polymers whereas complex carbohydrates function to control rates ...
*August 15, 2015*

**Math**

no idea. What shape is the container? Do the marbles touch all of the nearest sides of the container? Only one side? Any sides at all? Lots of specifics left out here.
*August 15, 2015*

**pre-algebra**

4/5 x + 5 < -3 4/5 x < -8 4x < -40 x < -10
*August 15, 2015*

**math**

clearly the black tea is 1/4 of the total The price p is thus 10(2.40)+30(3.20) = 40p
*August 15, 2015*

**lasmocol**

figure the number of moles of the silver compound. Since 500cm^3 is 0.5 liters, the molarity is twice the # of moles.
*August 15, 2015*

**Urgent math**

the expansion of (a+b)^10 starts out with a^10, so the term with a^3 is C(10,7)a^3b^7 So, since you have a = 3x and b = -3, that would be C(10,7)(3x)^3(-3)^7 = 360(27x^3)(-2187) = -7085880x^3
*August 15, 2015*

**Urgent math**

the common difference is d=5 So, the nth term is 4 + 5(n-1) or, 5n-1
*August 15, 2015*

**Algebra ASAP**

an = 0.85 * 1.29^n Now just plug in n=6
*August 15, 2015*

**Math**

No way to tell. What size cake did those ingredients make?
*August 14, 2015*

**AHOOOGAAH! HOMEWORK DUMP!**

So many questions! So little work to show! This is what is affectionately known as a Homework Dump.
*August 14, 2015*

**Algebra 1**

If 5% is gone, that leaves 95% of the previous population. So, #3.
*August 14, 2015*

**Algebra 1 - eh?**

eh?
*August 14, 2015*

**math**

(x+y)(x-y) = 105 Since 105 = 3*5*7, I suspect that x-y is one of those values. Now, 105 = 3*35 or 5*21 or 7*15 So, we can try x-y=3 x+y=35 (x,y) = (19,16) x-y=5 x+y=21 (x,y) = (13,8) x-y=7 x+y=15 (x,y) = (11,4)
*August 14, 2015*

**Geometry**

Wouldn't it be x-30+x+76=180 2x+46=180 2x=134 x=67 thus 67-30=37 and 67+76=143
*August 14, 2015*

**Geometry**

<1 &<2 are a linear pair. m<1=x-30 & m<2=x=76. Find the measure of each angle.
*August 14, 2015*

**Geometry**

That would makem it 24 + 34 =58 T NMO = 6(24)-28 58 + nmo = 144 - 28 = 119 116- 58 = 58 Thank you
*August 14, 2015*

**Geometry**

Line MO bisects <LMN, m<LMN =6x-28,m<LMO=x+34. Find m<NMO
*August 14, 2015*

**Math**

4/3 the speed means 3/4 the time. time = distance/speed
*August 14, 2015*

**math**

starting with x, .05x on rent, leaving .95x .95x * .20 = .19x on car, leaving .76x of the remainder, 7/20 = 4907, so 13/20 = 9113 So, 9113+4907 = .76x x = 18447.37
*August 14, 2015*

**Geometry**

since BD bisects the angle, we must have] 5x = 3x+10 2x = 10 x = 5 So, you are correct, but that does not answer the question: What is <ABC?
*August 14, 2015*

**Geometry**

sorry = my answer is 5
*August 14, 2015*

**Geometry**

Find the,<ABC if the line BD bisects <ABC and given m<ABD = 5x and m<DBC = 3x + 10.
*August 14, 2015*

**math**

since time=distance/speed, x/5 + 1/2 + x/(5/2) = 4 x = 35/6 His total distance is 2x
*August 14, 2015*

**math**

net inflow is 4 - 1/2 = 7/2 gal/min So, it takes 50/(7/2) = 14.3 min to fill
*August 14, 2015*

**Calculus**

Since x has degree less than x^2-100, the horizontal asymptote is y=0 since x^2-100 = 0 at x = ±10, and x≠0, those are the vertical asymptotes I find the function unrealistic. It implies negative concentrations, going off the charts as time increases. I suspect a ...
*August 14, 2015*

**Math**

x - x/5 - 2x/3 = 60 x(1 - 1/5 - 2/3) = 60 x(15-3-10)/15 = 60 x(2/15) = 60 x = 60(15/2) = 450
*August 14, 2015*

**college algebra**

Assuming you mean 3^(1-x) = 1/27 3^(1-x) = 3^(-3) 1-x = -3 x = 4
*August 14, 2015*

**algebra 2**

1st digit: 1-9 other digits: 0-9 So, 9*10*10*10 = 9000 possibilities
*August 14, 2015*

**Algebra ASAP**

find r by dividing any term by the previous term: r = 9/36 = 1/4 So, Tn = 36*(1/4)^(n-1) = 144/4^n T10 = 144/4^10 This was pretty straightforward. Looks like you need to review the topic.
*August 14, 2015*

**Algebra**

If the shorter list has x items, then x + x+7 = 33
*August 13, 2015*

**algebra**

5ac+10ab-25ad = 5a(c+2b-5d) 4x(a+b)-3y(a+b) = (4x-3y)(a+b) ax-bx+2a-2b = x(a-b)+2(a-b) = (x+2)(a-b) 2(x+y)-t(x+y) = (2-t)(x+y) These are pretty straightforward. Look how they worked out, and try some more on your own. It just takes a little practice to get used to seeing the ...
*August 13, 2015*

**physics**

see related questions below.
*August 13, 2015*

**calc**

clearly that would be ∫[0,2] t^2-1 dt = 2/3 But that is the algebraic distance (final displacement), since it starts out with negative velocity. To get the actual distance traveled, you need to separate the two parts: ∫[0,1] -(t^2-1) dt + ∫[1,2] t^2-1 dt = 2/...
*August 13, 2015*

**Math**

you are correct.
*August 13, 2015*

**Math**

Looks like you need to study what 50% more efficient means. It means B can do 50% more work than A in a given time. 50% = 0.5 So, 50% more means 1.5 times as much. That's 3/2. Think about it. If I do twice as much as you, it takes half (1/2) as long. If I do 3/2 as much as...
*August 13, 2015*

**Math**

3/2 as productive means it takes 2/3 as much time. So, (D).
*August 13, 2015*

**Math**

-4 = 0-4, but -1 ≠ 5-4
*August 13, 2015*

**Math**

Doesn't look like it, assuming I have read your garbled text correctly.
*August 13, 2015*

**Math Urgent**

well, let's see what happens. 12 6 3 10 5 16 8 4 2 1 4 2 1 4 2 1 tarting with T8, they repeat with a period of 3 1000 = 7+993 = 7+3*331 So, T1000 = 1
*August 13, 2015*

**STATISTICS**

looks like 0.12^3 to me.
*August 13, 2015*

**Math Probability**

clearly one step will take the ant to the equator of the octahedron. From there, there are 4 ways to go, only one of which continues on to the bottom. So, p = 1/4
*August 13, 2015*

**English**

thank you
*August 13, 2015*

**English**

Id the 2 adjectives. Argyles are patterned socks named after a Scottish clan. My answer patterned & Scottish
*August 13, 2015*

**Sociology**

thank you
*August 13, 2015*

**Sociology**

Understanding what is required to test theories? a- reason b- imagination c- validity research my answer is d
*August 13, 2015*

**math**

(6*42)/36 = 7
*August 13, 2015*

**Applied Geometry**

The area of an equilateral triangle with sides of 3 is 1/4 * 3^2 * √3 So, the volume of the pyramid is 1/3 (9√3/4)(4) = 3√3 = 5.2 You are correct.
*August 13, 2015*

**Geometry**

Nope. The whole circumference is 2πr = 16π
*August 13, 2015*

**Maths**

ok. now what?
*August 13, 2015*

**Maths**

do you mean 4√(132/143) - 2 or ∜(132/143) - 2 Not sure what "by" means here. Either way, there's not much that can be simplified. 132/143 = 11*12 / 11*13 = 12/13
*August 13, 2015*

**maths**

s/3 + 3t/4 = 30.5 2t = 6(j-s) j=34 solve that and you have s=24 t=30
*August 13, 2015*

**Math**

Just write down in symbols what they told you. If there are a apples and p pears, then a+p = 450 (1/2)a + (3/4)p = 265 a=290 p=160 a-p = 130
*August 13, 2015*

**math**

Which ways can two of the 15 coupons total $10? 2+8 5+5 8+2 P(2,8) = 5/15 * 2/14 = 1/21 P(5,5) = 2/15 * 1/14 = 1/105 P(8,2) = 2/15 * 5/14 = 1/21 Add up the ways and you get 11/105
*August 13, 2015*

**math**

20*15*6.00 = ?
*August 13, 2015*

**Arithmetic progession**

a+2d = 10(a+d) a+6d = 7a Solve for a and d, and then you can find the sum of T8+T15 = (a+7d)+(a+14d)
*August 13, 2015*

**MATH**

well, since there are 360° for 24 hours, every hour is 15° of longitude. The latitude does not matter.
*August 13, 2015*

**Urgent math**

well, finding the first six terms is easy, right? An = 5n^2-1, so here's a table: n An 1 5*1^2-1 = 5-1 = 4 2 5*2^2-2 = 20-2 = 18 3 5*3^2-3 = 45-3 = 42 4 5*4^2-4 = 80-4 = 76 5 5*5^2-5 = 125-5 = 120 6 5*6^2-6 = 180-6 = 174 Now just add 'em up to get S6
*August 12, 2015*

**Calculus**

just to get rid of pesky decimals. Fractions are exact; decimals can often be only an approximation, as in 2/3 = 0.666...
*August 12, 2015*

**Math**

If there were c correct answers, then there were 10-c wrong answers. So, now use her score to find c: 5c - 2(10-c) = 29
*August 12, 2015*

**Math (Calculus)**

you need both the product rule and the chain rule. f(x) = (3x)(x^2+4)^-1 f'(x) = (3)(x^2+4)^-1 + (3x)(-1)(x^2+4)^-2(2x) = 3/(x^2+4) - 6x^2/(x^2+4)^2 = (3(x^2+4)-6x^2)/(x^2+4)^2 = (12-3x^2)/(x^2+4)^2 The quotient rule produces the same result; in fact, you can see the ...
*August 12, 2015*

**math**

time of truck: 15:24-12:00 = 204 minutes time of flight: 3:24-1:48 = 96 minutes So, if the truck's speed was x km/hr, we have (x km/hr)(204 min) = (170 km/hr)(96 min) x = 170*96/204 = 80 You could convert everything to m/s, or use fractional hours or something, but if you ...
*August 12, 2015*

**Math**

If you google images for "ruler" you will find many images. Some have an inch divided into 16 parts, and some into only 8 parts. If you remember that 1/8 = 2/16, you should have no trouble getting what you want.
*August 12, 2015*

**Geometry**

If BC=2y and CD=2x, note that triangles ADF, ECF, and ABE are all right triangles with one leg half of a side of the rectangle. We know that ABCD has area (2x)(2y) = 72, so xy=18. ADF has area (2y)(x)/2 = xy = 18 ECF has area (y)(x)/2 = xy/2 = 9 ABE has area (y)(2x)/2 = xy = ...
*August 12, 2015*

**Algebra**

If there were c correct answers, then there were 10-c wrong answers. So, now use her score to find c: 5c - 2(10-c) = 29
*August 12, 2015*

**alegebra**

AP: T1 = a T3 = a+2d T9 = a+8d GP: T1 = a T2 = ar T3 = ar^2 a+6d = 14 a+2d = ar a+8d = ar^2 Solve all that and you find a=2 d=2 r=3 T20 of the AP is 2+19*2 = 40 Check: AP: 2 4 6 8 10 12 14 16 18 20 ... GP: 2 6 18 ...
*August 12, 2015*

**Algebra 2**

You know that y=5x+2 has slope 5. Now just use the point-slope form of the line: y+3 = 5(x-1) You can massage that into one of your choices, if it's not already there.
*August 12, 2015*

**Algebra ASAP**

P: 3^(2n)-1 is a multiple of 8 P(1): 3^2-1 = 8. True Assume P(k). Then with n=k+1, we have 3^(2(k+1))-1 = 3^(2k+2) = 3^(2k)*9 - 1 = 3^(2k)*8 + 3^(2k) - 1 but, we know that 3^(2k)-1 is a multiple of 8, say, 8m. Then we have =8(3^(2k))+8m = 8(3^(2k)+m) which is a multiple of 8. ...
*August 12, 2015*

**pre-cal**

The term containing x^k in (x+z)^n is C(n,n-k)x^(n-k)z^k. So, we have C(10,5)(x^5)(2y)^5 = 8064 x^5 y^5
*August 12, 2015*

**math**

(a+b)^2 = 49 (a-b)^2 = 16 (a+b)^2 - (a-b)^2 = 4ab = 33 so, ab = 33/4
*August 12, 2015*

**algebra 1**

As written, f(x) = 5x-1 So, you will have a shifted f as g(x) = f(x-13) = 5(x-13)-1 = 5x-66 If, however, your function is f(x) = 5(x-1), then the shifted function is g(x) = f(x-13) = 5((x-13)-1) = 5(x-14) You gotta learn how to use parentheses!!
*August 12, 2015*

**Counting and Probability**

Take a look in each hundred numbers starting with the digit x: x10 x20 ... x90 - 9 of them x21 x31 ... x91 - 8 of them ... x98 - 1 of them 9+8+...+1 = 45 So, in each hundred numbers there are 45 that have the tens greater than the ones.
*August 12, 2015*

**math**

Clearly the equation is wrong. If a = π/4, we have sina = cosa = 1/√2 and the equation is 1/8 + 1/8 - 1/8 = 1 - 2(1/2) which is false.
*August 12, 2015*

**Math**

If the number is ab, then we have 2(a+b) = b+19 10b+a = 10a+b - 18 Now solve for a and b, and you see that the number is 75
*August 12, 2015*

**algebra**

any value of r such that 0 < 1+r < 1 will work. That is, -1 < r < 0 In other words, r is negative, but not by much. That is, (1+r) is a positive fraction, so as x increases, the value of A(x) gets smaller and smaller
*August 12, 2015*

**Math**

(j/2) = (j/k)(k/2) = (32)(3/4) = 27
*August 12, 2015*

**pre-cal**

In Pascal's Triangle, the coefficients on the 5th row are 1,5,10,10,5,1 So, (x-y)^5 = x^5 + 5(x^4)(-y) + 10(x^3)(-y)^2 + 10(x^2)(-y)^3 + 5x(-y)^4 + (-5)^5 = x^5 - 5x^4y + 10x^3y^2 - 10x^2y^3 + 5xy^4 - y^5
*August 12, 2015*

**probability**

well, they tell you that the probability that the archer hits the target exactly r times in n attempts is given by the term containing p^r in the binomial expansion of (p+q)^n You have p=0.8 and q=0.2 You want the term containing p^4 in the expansion of (p+q)^6 That term will ...
*August 12, 2015*

**calculus**

xy^3 + 2y - 2x = 1 y^3 + 3xy^2 y' + 2y' - 2 = 0 y' = (2-y^3)/(3xy^2+2) At (1,1), y' = 2/5 Now you have a point: (1,1) and a slope: 2/5 I'm sure you know the point-slope form of a line.
*August 12, 2015*

**calculus**

tantas preguntas! tan poco trabajo!
*August 12, 2015*

**math**

If the square has side x, then the box when folded up has height 5, and a square base of side x-5-5=x-10 5(x-10)^2 = 320 (x-10)^2 = 64 x-10 = 8 x = 18
*August 12, 2015*

**Math**

If the squares have sides a and b, then we have 4a+4b=20 a^2+b^2 = 13 a+b=5 (a+b)^2 = 25 a^2+b^2+2ab = 13+2ab = 25 2ab=12 ab=6 If we assume integer sides, then since the factors of 6 are 2 and 3, a=2, b=3. check: 4*2+4*3 = 20 2^3+3^2 = 13 OK
*August 12, 2015*

**Maths progression**

we have a=2 sum of 1st 5 terms: S5 sum of next 5 terms: S10-S5 So, we now have S5 = (S10-S5)/4 4S5 = S10-S5 5S5 = S10 (5)(5/2)(4+4d) = (10/2)(4+9d) d = -6 The progression is thus 2, -4, -10, -16, -22, -28, -34, -40, -46, -52 ... S5 = -50 S10 = -250 S10-S5 = -200 T20 = 2+19(-6...
*August 12, 2015*

**math or algebra**

rate of change is °/hr You have 12° in 6 hrs Thus the average rate of change is -12°/6hr = -2°/hr the distance from sea level is just the absolute value of the elevation. That is, +500 ft and -500 ft are both just 500 ft from sea lavel. So, Climax: |11560| = ...
*August 12, 2015*

**physics**

0.544 km E = <0.544,0.000> 0.925 km S = <0.000,-0.925> 3.58 km W17.3°N = <-3.418,1.065> Adding them all up, the final location is <-2.874,0.140> Now you should be able to figure the final displacement and thus the average velocity.
*August 12, 2015*

**math**

20 cos30°
*August 12, 2015*

**Polygon**

5*180 / 7
*August 12, 2015*

**Algebra**

done - see previous posting.
*August 12, 2015*

**Urgent math**

none - see previous post.
*August 12, 2015*

**Geometric progression**

clearly, a=6, r=3/2 S13 = a(r^13-1)/(r-1) = 6((3/2)^13 - 1)/(3/2 - 1) = 4758393/2048
*August 11, 2015*

**math**

done. see prior post.
*August 11, 2015*

**math**

done - see previous post
*August 11, 2015*

**math**

done. see previous post
*August 11, 2015*

**DC/AC Electronics**

highest, since E = IR or IX
*August 11, 2015*

**math**

LCM(4,7,8,9) = 504 5:4 = 630:504 7:8 = 504:576 9:7 = 576:448 So, we have the class ratios in the sequence 630:504:576:448 Add those up and you have 2158
*August 11, 2015*

**math**

As usual, draw a diagram. If the smaller circle has center O and the larger circle has center P, and the tangent on one side touches O at A and P at B, then draw AC parallel to OP, intersecting PB at Q. Note that AQ = OP and you have a right triangle AQB where angle QAB = 30&...
*August 11, 2015*

**math**

(x)(t+54) = (1.12x)t tx + 54x = 1.12tx .12tx = 54x .12t = 54 t = 450 The actual value of x does not matter.
*August 11, 2015*

**algebra 2**

well, 1+cot^2 = csc^2 tan(cot+tan) = 1 + tan^2
*August 11, 2015*

**mathematics**

I can't see how two forces of 35 and 5 can add up to 5. 35-5 <= |u+v| <= 35+5 I suspect a typo
*August 11, 2015*

**Urgent math**

I don't see any which work 5(1)+1-9 = -3 6(4)-2 = 22 7(2)+1 = 15 3(2)+1 = 7 10(2)-2 = 18
*August 11, 2015*