This are the right steps
Step 1: first you divide the both size by 7 because there is 7 a's
7a/7 = 28/7
Step 2: You solve the equation
7a/7= a. 28/7 = 4
So, the answer is a = 4
not 7 = 4
Answer:
2 hrs 13 mins
Step-by-step explanation:
If Richard can paint the living room in 4 hrs, then in 1 hour he can paint 1/4 of the living .
If Vanessa can paint the living room in 5 hours, then in one hour, she can paint 1/5 of the living room.
In one hour Richard and Vanessa can paint 1/4 + 1/5 = 1/y
y is the number of hours it will take both Richard and Vanessa to paint the living room. 1/y is how much of the house they can paint in one hour.
1/4 + 1/5 = 1/y
(5 + 4)/20. ( find the LCM)
9/20 = 1/y
9y= 20
y = 20/9
y = 2.22hrs
y = 2 hrs 13 mins
$2.50
Hope this helps!
May I have brainliest? :D
Answer:
The simplest form of 1/2 x 2 is 2 or 2/1 or 4/2.
The simplest form of 3/8 is 3/8.
Step-by-step explanation:
(look at picture)
First, we have to convert our function (of x) into a function of y (we revolve the curve around the y-axis). So:

And the derivative of x:

Now, we can calculate the area of the surface:

We could calculate this integral (not very hard, but long), or use
(1),
(2) and
(3) to get:



Calculate indefinite integral:

And the area:
![A=2\pi\int\limits_0^{10}x\sqrt{4x^2+1}\,dx=2\pi\cdot\dfrac{1}{12}\bigg[\left(4x^2+1\right)^\frac{3}{2}\bigg]_0^{10}=\\\\\\= \dfrac{\pi}{6}\left[\big(4\cdot10^2+1\big)^\frac{3}{2}-\big(4\cdot0^2+1\big)^\frac{3}{2}\right]=\dfrac{\pi}{6}\Big(\big401^\frac{3}{2}-1^\frac{3}{2}\Big)=\boxed{\dfrac{401^\frac{3}{2}-1}{6}\pi}](https://tex.z-dn.net/?f=A%3D2%5Cpi%5Cint%5Climits_0%5E%7B10%7Dx%5Csqrt%7B4x%5E2%2B1%7D%5C%2Cdx%3D2%5Cpi%5Ccdot%5Cdfrac%7B1%7D%7B12%7D%5Cbigg%5B%5Cleft%284x%5E2%2B1%5Cright%29%5E%5Cfrac%7B3%7D%7B2%7D%5Cbigg%5D_0%5E%7B10%7D%3D%5C%5C%5C%5C%5C%5C%3D%20%5Cdfrac%7B%5Cpi%7D%7B6%7D%5Cleft%5B%5Cbig%284%5Ccdot10%5E2%2B1%5Cbig%29%5E%5Cfrac%7B3%7D%7B2%7D-%5Cbig%284%5Ccdot0%5E2%2B1%5Cbig%29%5E%5Cfrac%7B3%7D%7B2%7D%5Cright%5D%3D%5Cdfrac%7B%5Cpi%7D%7B6%7D%5CBig%28%5Cbig401%5E%5Cfrac%7B3%7D%7B2%7D-1%5E%5Cfrac%7B3%7D%7B2%7D%5CBig%29%3D%5Cboxed%7B%5Cdfrac%7B401%5E%5Cfrac%7B3%7D%7B2%7D-1%7D%7B6%7D%5Cpi%7D)
Answer D.