Sunday

February 26, 2017
Total # Posts: 48,795

**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*

**math**

sorry, an extra point is awarded by scoring an "extra point". A field goal is worth 3 points. At any rate, if they get the extra point after each touchdown, then their score for x touchdowns is y = 6x + 1x = 7x Saying the total score for "x" amount of ...

*February 6, 2017*

**physics**

(6000kg*9.8N/kg)/(4*.10m^2) = 147000N/m^2 = 147KPa

*February 6, 2017*

**physics**

what volume of water has a mass of 400kg? Divide that by 24m^2 to get the depth of the displaced water.

*February 6, 2017*

**physics**

2700 kg * 1m^3/1.25kg = 2160 m^3

*February 6, 2017*

**Accelerated 1**

# coins = c points = p point for star = 3p p = 10c

*February 6, 2017*

**Math**

If you mean y = 9x1/2 it is not even exponential. An exponential function has x in the exponent, such as y = 9 * (1/2)^x which would be decay, because powers of fractions get progressively smaller. If you don't know how to even make a chart, you are in trouble. For a chart...

*February 6, 2017*

**Math**

since time = distance/speed, 7.2*10^2km / 1.2*10^3km/hr = 0.6hr Now convert to minutes.

*February 6, 2017*

**astronomy**

mirrors, lenses

*February 6, 2017*

**Algebra 2 help**

Oh, please. In the first, place, you'd better go out and get a calculator. Or use your phone's calculator. Or, there are lots of calculators online. google, etc. wolframalpha.com allows you to give a formula and a value, such as http://www.wolframalpha.com/input/?i=4x...

*February 6, 2017*

**math help quick please**

stop guessing. Next step: 5x+2x-14 = 7 ... B works for the 1st equation, but not the second.

*February 6, 2017*

**math help quick please**

so, substitute y=x-7 into 5x+2y = 7 5x+2(x-7) = 7 ...

*February 6, 2017*

**Math**

see related questions below.

*February 6, 2017*

**Algebra**

x^3 + 5x^2 - 4x - 2 = (x-1)(x^2+6x+2) The discriminant of the quadratic is positive, so it has two real roots.

*February 6, 2017*

**math**

(3/8) / (3/4) = 3/8 * 4/3 = 1/2 Naturally. Since 1/8 is half as big as 1/4, so are three of them half as big as three fourths.

*February 6, 2017*

**Maths**

I think you meant 4;7;10;13 where An = 1+3n So, just solve for n where 1+3n > 150

*February 6, 2017*

**Algebra**

using the sum of two cubes, (x + 3)^3 + 10 = (x+3+?10)((x+3)^2 - (x+3)?10 + ?100) = x^2 + (6-?10)x + (?100-3?10+9) One root is clearly x = -(3+?10). You can see that the discriminant of the quadratic is negative, so there are no other real roots. Or, consider the graph. It is ...

*February 6, 2017*

**Trig**

since sin(x) = cos(?/2-x) arccos(t) + arcsin)t) = ?/2 In general, draw the triangle. In this case, take cosine of both sides. cos(arccos(t)) = t In your triangle, the adjacent side will be t, and the hypotenuse will be 1. The other leg is thus ?(1-t^2). So, sin(arccos(t)) = ?(...

*February 6, 2017*

**MATH**

The odds are 7:4 beat 4:7 lose, so 4/11 probability

*February 6, 2017*

**Calculus**

This is a trick question, in a way. You can go through the math of height and speed, using an unknown acceleration (you will find that this fails to have a solution when g=9.8 is used). Or, you can just note that since momentum is conserved, the speed at launch is exactly the ...

*February 6, 2017*

**Math**

the unknown sides are equal, say x. So, 54+x+30+x = 134 If you draw your trapezium and mark off the interior 30x30 square, you will find a right triangle at each end, with base 12 and hypotenuse x. So, the height of the trapezium is ?(x^2-144) making the area A = (30+54)/2 ?(x...

*February 6, 2017*

**algebra 2**

you need to get your typing straight × is the symbol for multiplication x is a variable name 9 (9 - 8x) = 2x + 3 81 - 72x = 2x + 3 78 = 74x x = 78/74 = 39/37 Note that you cannot subtract the 2x inside the parentheses. You have to expand the left side first. Try it with ...

*February 6, 2017*

**algebra 2**

[-4b -8] + [-1b -b^2] + 2b^3 plug in b=2 (-4(-2) - 8) + (-1(-2) - (-2)^2) + 2*(-2)^3 (8-8) + (2-4) + 2(-8) 0 - 2 - 16 -18

*February 6, 2017*

**Math**

400 mL of 1/2 strength juice contains 200 mL of juice Adding 100 mL of juice makes 500 mL containing 300 mL juice, or 60% juice.

*February 6, 2017*

**math**

Change the fractions to have the same denominator: 1/3 , 5/6 , 4/3 = 2/6, 5/6, 8/6 The numerators are 2,5,8 Clearly, 3/6 = 1/2 is added each time.

*February 6, 2017*

**Maths**

density of A: 1.2kg/(20*10*5)cm^3 = 1.2/1000 = 0.0012 kg/cm^3 = 1.2 g/cm^3 Block B is 6cm on a side, with a density of 1.2*1.4 = 1.68 g/cm^3 So, its mass is 1.68 g/cm^3 * 216cm^3 = 362.88 g = 0.36 kg

*February 6, 2017*

**math**

The amount of work is 8hr/day * 13men * 15day = 1560 man-hr So, you want x so that 10*26*x = 1560 x = 6 days

*February 6, 2017*

**Algebra (plz)**

(a+b)^2 = a^2 + 2ab + b^2 You need the first and last terms to be perfect squares, and the middle term to be twice their product. 4m^2-4mp+p^2 = (2m-p)^2 16s^2+56s+49 = (4s+7)^2 16c^2+72cd+81d^2 = (4c+9d)^2

*February 6, 2017*

**las st**

The vertical and horizontal distance components of the flare are y = 2400 + 120t - 4.9t^2 x = 207.84t The flare hits the ground when t=37.54 The tangent of the angle of direction at time t=37.54 is dy/dx = (120-9.8*37.54)/207.84 = -1.193 So, ? = -50° I am assuming that the...

*February 6, 2017*

**Math**

Hmmm. If m is the number of correct answers, then s = 5m-3(10-m) = 8m-30

*February 5, 2017*

**math**

I expect some information about g will help ...

*February 5, 2017*

**Intermediate Algebra**

same problem: If there are x liters of 25%, then the rest (50-x) is 60%. So, .25x + .60(50-x) = .40 * 50

*February 5, 2017*

**Algebra**

48/5

*February 5, 2017*

**Math**

it gains 1 meter each day. After 9 days it has climbed 9 meters On the 10th day it climbs 3 meters and is out.

*February 5, 2017*

**Math**

so, is -18 the max or the min? There is a double root at x=1, where it just touches the x-axis. It crosses the x-axis at x = -4 Since this is a cubic polynomial, with negative leading coefficient, it drops down from the left. So, it is decreasing on (-?,-4) and beyond to the ...

*February 5, 2017*