# Posts by steve

Total # Posts: 49,627

**MATH TEST(tipps)**

As longs as you're studying, work on your English: I have a math test in a week; plz give me some tips so I can pass it

*February 11, 2017*

**maths**

well, if u = x-y v(u) = u/3

*February 11, 2017*

**maths**

A*(x,y)T = (4,4)T (x,y)T = A-1(4,4)T

*February 11, 2017*

**Algebra 2**

Not sure I get this step, since ^ is right-associative: 3^(1/2)^x = a^(1/6) 3^3^x = a As written, that means 3^(3^x) I was thinking (3^(1/2))^x = a^(1/6) 3^(x/2) = a^(1/6) 3^(3x) = a 3^3 = a^(1/x) = a^b 1/x = b x = 1/b

*February 11, 2017*

**Math**

(203/2.2)/40 * 10 = 23.07 mg

*February 11, 2017*

**Calculus 2**

actually, it appears I was right after all...

*February 10, 2017*

**Calculus 2**

I may have misspoken. Take a look here for a discussion of the topic. faculty.atu.edu/mfinan/2243/business65.pdf

*February 10, 2017*

**Calculus 2**

Money at 2% grows like e^0.02t The amount deposited at time t gets to grow for (9-t) years. Seems to me like the account balance after 9 years is thus ?[0,9] R(t) * e^(.02(9-t)) dt

*February 10, 2017*

**math**

(1 1/2)(1/2) = 3/4 So, the new dimensions are 3/4 the original ones. You can do the math now...

*February 10, 2017*

**Algebra**

see related questions below.

*February 10, 2017*

**Algebra**

Not sure just what you're after. If the sums in the ratio 3:1 are just the first five terms, then a^2(1-r^10)/(1-r^2) ------------------------- = 3 a(1-r^5)/(1-r) ar = 4/3 a = 4/(3r), so plug that in, and (4/(3r))^2(1-r^10)/(1-r^2) ------------------------- = 3 4/(3r)(1-r^...

*February 10, 2017*

**Math**

cutting out the fat (!) (16^2/6^2) * 630 / 8 = 560

*February 10, 2017*

**Math**

3/5 x + 100 = 2/3 x x is in mL Now just solve for x. And that's liters, not literature!

*February 10, 2017*

**Mathematics**

the volume of the orange is ? * 12^2 * 6.75 = 972? cm^3 Now use what you know about the volume of a sphere to get the radius of the orange, and thus its surface area.

*February 10, 2017*

**Math College freshman**

(-100-20)/(40-20) = -6 so, the slope is -6, and we start with h = -6x But -6(20) = -120, and h(20) = 20. So h(x) = -6x + 140 You can check to make sure this fits the other points as well.

*February 10, 2017*

**College Algebra**

.15*5 = 0.75 So, T = .15p+0

*February 10, 2017*

**Math 115**

Clearly, W = 5x+5 The answer key must have an error.

*February 10, 2017*

**Math**

correct on both

*February 9, 2017*

**Cmax**

Any decent calculator has a button for ex somewhere. Probably an alternate function for ln.

*February 9, 2017*

**Science**

the filament has electrical resistance. When electricity passes through it, it generates heat -- so much heat that the wire glows.

*February 9, 2017*

**math**

Nope. The rate of growth is the slope of the line. Study (D) to see why it is the choice.

*February 9, 2017*

**math**

(b^2)^0 = 1 = b^8 So, b = 1 or -1 Just use the rules of exponents as usual. Negative values are still just numbers! p(p^-7q^3)^-2q^-3 = p * (p^-7 q^3)^-2 * q^-3 = p * p^14 q^-6 * q^-3 = p^15 q^-9

*February 9, 2017*

**Math**

.49p = 72.89

*February 9, 2017*

**math**

try writing them as 26x - 12y = 4 9x - 12y = -30 Now just subtract the equations and the y's will vanish.

*February 9, 2017*

**English**

Bob, I am a 70-year-old grandfather trying to help his grandson. Yes, I have read the book. After going and checking the difference between limited and omniscient I would say that the right answer should be 1st person omniscient.

*February 9, 2017*

**English**

The great gatsby is written in which point of view. 1st person limited 1st person omniscient 3rd person limited My answer is c

*February 9, 2017*

**Calculus prince@18**

h(x) = ?[2,x^2] arctan(t) dt from the 2nd Fundamental Theorem of calculus (and the chain rule), h'(x) = arctan(x^2) * 2x if F(t) = ?arctan(t), then h(x) = F(x^2) - F(2) now the chain rule gives the result, and d/dx F(2) = 0 If we had had h(x) = ?[lnx,x^2] arctan(t) dt then...

*February 9, 2017*

**math**

1 3/2 is bogus. Mixed numbers do not generally have a fractional part greater than 1. Anyway, 3^2 = 9 1 3/2 = 5/2 = 2.5 and now it should be clear. Do the others by putting them all over a common denominator (8), and then just sort the numerators.

*February 9, 2017*

**PHYSICS**

the fine article in wikipedia on "trajectory" explains this and more. The formula for the range is R = v^2/g sin(2?)

*February 9, 2017*

**Math**

the slope is -3/5 So, now you have a point and a slope. The line is y-4 = -3/5 (x+6) They don't call it the "point-slope" form for nothing!

*February 9, 2017*

**Algebra II**

neither one is. (a+b)^2 = a^2 + 2ab + b^2 neither one of these has a middle term. No idea what the "original monomial" could be. x? 4? 2?

*February 9, 2017*

**math**

why ever would you subtract radius from height? The volume of towels is the volume of the whole package, minus the volume of the inner cylinder. Recall that the volume of a cylinder is v = ?r^2 h. So, the volume of the towels is ?*12^2*18 - ?*5^2*18 = 2142? cm^3

*February 9, 2017*

**Math/Chemistry**

Have you forgotten your Algebra I? Ao/A = kt Ao = Akt

*February 9, 2017*

**Geometric problem solving**

first off, the circumference is measured in meters, not m^2. If C = 2?^2, then 2?r = 2?^2 r = ? So, A = ?r^2 = ?^3 m^2 If you meant to find the circumference when the area is 2?^2 m^2, ?r^2 = 2?^2 r^2 = 2? r = ?2? C = 2?r = 2??2? = (2?)^(3/2) Actually, I think you just messed ...

*February 9, 2017*

**math**

convert all to have the same power of 10, then it will be clear. For example, 2.3 * 10^5 = 230 * 10^3

*February 9, 2017*

**Math**

1/6 * 1/6 * 1/6

*February 9, 2017*

**Precalculus**

<k,2>•<3,5> = 0 3k+10 = 0 k = -10/3 gotta watch those ± signs!

*February 9, 2017*

**Math**

13/14 = 0.92857 = 92.857% The remainder from 13/14 is 13! Try some other number, say 72/13 = 5 7/13 = 5 R 7 The remainder is always less than the divisor, so 13/14 = 0 13/14 = 0 R 13

*February 8, 2017*

**Finance**

Which type of debt is the least attractive for a consumer? Unsecured debt Secured debt Mortgage debt Lease debt My answer is unsecured debt

*February 8, 2017*

**Math**

2(4+6) * $4.84

*February 8, 2017*

**Math**

no, that would make the answer 8m=102 ...

*February 8, 2017*

**math**

Note that you have two right triangles, with a common angle. So, they are similar, with all angles equal.

*February 8, 2017*

**Algebra**

well the function f is usually written in the form f(x) = 2x-2 so D looks like the choice intended. But saying Volume(radius) = 67 is a bit strange, since it implies that no matter which value "radius" has, the Volume remains constant at 67. If the value of Volume is...

*February 8, 2017*

**math**

I see that this time you omitted the instructions to make a Venn diagram. Did you do that, or are you just waiting for the answers? It appears that you must have meant 6 study only biology since you already said that 60 study biology. I think there is still something missing ...

*February 8, 2017*

**Math**

You might have check my solution given earlier before reposting the problem: http://www.jiskha.com/display.cgi?id=1486538658

*February 8, 2017*

**examples of pop singers**

Do you have some inappropriate ones in mind???

*February 8, 2017*

**math**

There are lots of online calculators, such as https://www.emathhelp.net/calculators/calculus-2/simpsons-rule-calculator/?f=1%2F%28x%5E5%2B7%29%5E%281%2F3%29&a=0&b=1&n=4&steps=on

*February 8, 2017*

**anonymous**

well, how many moles of CO2 in 66.50 grams? Use that and your balanced equation to see how many moles of benzene you need. Then convert back to grams.

*February 8, 2017*

**math**

well, you know that 2x = y-14 So, use that in the other equation: -4x = -2(2x), so -2(y-14)-y = 14 ...

*February 8, 2017*

**English**

exactly backwards. If the first sentence had to include the "was" then it is a progressive tense: was helping. Becca was {helped/helping} Corky with his homework last night. Similarly, the second sentence is a simple past tense: Blossom watched her best friend study ...

*February 8, 2017*

**Math**

28,000(1+2.5) = 98,000 70,000 is 250% of 28000, but that means that it increased by 150%. Gets kinda tricky, if you're not careful with the wording.

*February 8, 2017*

**math**

correct, assuming that Jack actually ate his slices ...

*February 8, 2017*

**math**

well, just do the math: .05 * 1250 = ?

*February 8, 2017*

**Math**

7:4 means the lemonade is 7/11 of the total. 7/11 = .6363 8:4 means 8/12 = .6666 I hope that was the reason you picked C.

*February 8, 2017*

**physics**

32@W = <-32,0> 11@N = <0,11> Resultant is <-32,11> = 33.8@W19°N

*February 8, 2017*

**Math**

If there are x students in all, 1/4 of the non-band students are in neither: 1/4 (x-12) = x/5 x/4-3 = x/5 x/20 = 3 x = 60 Check: 12 in band, leaves 48 others 36 in dance club 12 in neither

*February 8, 2017*

**math**

so, what is "the difference" of a circle?

*February 8, 2017*

**Continuity Calculus Help**

4x+3 = 11 at x=2 4x^2 = 16 at x=2 Since f(x) = 4x+3 for x <= 2, lim(x->2-) f(x) = 11 = f(2) But lim(x->2+) = 16 ? 11

*February 8, 2017*

**Math**

30/90 = 1/3 = 33.3%

*February 8, 2017*

**Math**

1/2(4x+2)+8x = (1/2)(4x) + (1/2)(2) + 8x = 2x+1+8x = 10x+1 time to review the distributive property: a(b+c) = ab + ac

*February 8, 2017*

**Math**

y = ax^3+bx^2+cx y' = 3ax^2+2bx+c y" = 6ax+2b Since y"=0 at x = -1, -6a+2b=0 3a-b = 0 y'=4 at x = -1, so 3a-2b+c = 4 y=-5 at x = -1, so -a+b-c = -5 Now you have the three equations 3a-b = 0 3a-2b+c = 4 a-b+c = 5 y = x^3+3x^2+7x The tangent line at (-1,-5) has...

*February 8, 2017*

**MAth**

well, all three angles add to 180...

*February 8, 2017*

**math**

just what does 85 of itself mean?

*February 8, 2017*

**maths equation too hard**

There is no general algebraic way to solve equations like this, but it should be easy to see that 3^3 = 3^3

*February 8, 2017*

**algebra**

c+r = 8.5 16c+8r = 112 Now just solve for c and r.

*February 8, 2017*

**Math**

y is the base Online, use ^ to indicate exponents, as in y^2 and y^4

*February 7, 2017*

**math**

since cos 2?/3 = -1/2, r(2?/3) = 0 So, the graph loops back to r=0 at ?=2?/3 Using symmetry, we need consider only the top half of the figure, so we just need to subtract the inner loop from the outer loop, giving us A/2 = ?[0,2?/3] 1/2 r^2 d? - ?[2?/3,4?/3] 1/2 r^2 d? A = ?[0...

*February 7, 2017*

**math**

It's easier to find the number of quarters: 10*3q + 25q = 385 55q = 385 q = 7 so, d=3q=21

*February 7, 2017*

**Maths**

assuming you meant 1/x + 1/(x+1) = 1 x+1 + x = x(x+1) x^2-x-1 = 0 ...

*February 7, 2017*

**Maths**

y/x * 80p

*February 7, 2017*

**Math**

80/10 = 8 bags

*February 7, 2017*

**math**

possibilities for what? a little more context would help.

*February 7, 2017*

**math**

-7/4 -73/100

*February 7, 2017*

**Geometry**

recall that the diagonals of a rectangle are equal.

*February 7, 2017*

**Math**

You just need to review the meanings of the 1st and 2nd derivatives. y = 3x^4-10x^3+12x^2+12x-7 y' = 12x^3-30x^2+24x+12 = y" = 36x^2-60x+24 = 12(3x-2)(x-1) max/min where y'=0 inflection where y"=0 max if y'=0 and y"<0 min if y'=0 and y"&...

*February 7, 2017*

**math**

3.14*10^8 --------------- = 0.046 or 4.6% 6.8*10^9

*February 7, 2017*

**Math Limits**

(a) 4 (b) 15 (c) -15

*February 7, 2017*

**Math - Continuity of Functions**

(x-2)/(?x-?2) = [(?x-?2)(?x+?2)]/(?x-?2) = ?x+?2 for all x?2 So, if k=2?2 f is continuous everywhere.

*February 7, 2017*

**Maths**

Draw a diagram. It should be clear that h cot60° = (h-10) cot30°

*February 7, 2017*

**Math - Continuity of Functions**

since |sin(1/x)|<=1 x*sin(1/x) -> 0 as x->0 f(0)=0 will make f defined everywhere.

*February 7, 2017*

**math**

Just use the point-slope form and pick any three values for the slope m: y+2 = m(x-6)

*February 7, 2017*

**math**

In retrospect, it would probably have been easier to work this one backwards, with no algebra: After round 3: 10,10,10 After round 2: 5,20,5 and so on...

*February 7, 2017*

**math**

If the start with amounts x,y,z after the 3 rounds, the holdings are x-y-z, 2y, 2z 2(x-(y+z)),4y,2z-(x-(y+z))-2y = 2x-2y-2z, 4y, 3z-x-y 2(2x-2y-2z), 4y-(2x-2y-2z)-(3z-x-y), 2(3z-x-y) = 4x-4y-4z, 7y-x-z, 6z-2x-2y So, now we have three equations: 4x-4y-4z = 10 -x+7y-z = 10 -2x-...

*February 7, 2017*

**maths**

From your sum-to-product formulas, sinA-sinB = 2 cos(A+B)/2 sin(A-B)/2 Using your values, that would be 2 cosx sin2y without knowing more about the relation between x and y, that's as far as we can go. If you supply the missing info, I'm sure you can finish it off.

*February 7, 2017*

**math**

k = m-4 k+3 = 2/3 (m+3) Now just solve for k and m.

*February 7, 2017*

**Math**

"10 to the power of 2" or 10^2 40 + x = 10^2 40+x = 100 . . .

*February 7, 2017*

**Math**

clearly the missing angle is 52° Find two corresponding sides with a known ratio, and use that ratio to find the missing values.

*February 7, 2017*

**science**

static electricity

*February 7, 2017*

**math**

If their ages are a < b < c then c = b+8 a = c-12 a+b+c = 88 ...

*February 7, 2017*

**mensuration**

6^2+8^2 = 10^2

*February 7, 2017*

**Question on Integration**

let x = 2sinh? x^2+4 = 4sinh^2?+4 = 4cosh^2? dx = 2cosh? d? Now the integral becomes ?x^3 / (x^2 + 4)^2 dx ?8sinh^3?/16cosh^4? 2cosh? d? ?tanh^3? d? see what you can do with that. using direct substitution, let u = x^2+4 du = 2x dx ?x^3 / (x^2 + 4)^2 dx (1/2)?x^2 / (x^2 + 4)^2...

*February 7, 2017*

**Algebra**

7d+2b = 11 2d+7b = 16 5d + 2(d+b) = 11 5b + 2(d+b) = 16 add the equations and you get 5(d+b) + 4(d+b) = 27 9(d+b) = 27 d+b = 3 similarly, b-d = 1 b=2 d=1 dog costs $1 burger costs $2

*February 6, 2017*

**Math**

Remember that a proportional relationship between x and y means that y = kx. There can be no extra constants floating around. A is a proportional relationship between y and x^2 Only C is a p.r between y and x. For #2, same thing applies.

*February 6, 2017*

**Algebra2**

Looks good to me

*February 6, 2017*

**Algebra2**

What is the product in simplest form? State any restrictions on the variable. 4a^5/7b^4 times 2b^2/2a^4 My answer is 4a/7b^2 except a=0 and b=0

*February 6, 2017*

**Math**

well, sinØ = 3/4 cosØ = ?5/4

*February 6, 2017*

**Math**

tan(-a) = -tan(a), so tan(a) = 5 so, cot(a) = 1/5

*February 6, 2017*

**Algebra2**

Thank you very much

*February 6, 2017*

**Algebra2**

Simplify the rational expression. State any restrictions on the variable. (n^4-11n^2+30)/(n ^4 -7n^2+10) My answer is n^2-6/n^2-2 except +-sqrt5 and +-sqrt2

*February 6, 2017*