All you've got to do is some simple algebra! When you solve for a variable, you are trying to get it alone on one side of the equation. So, we want something that looks like y = ...
First, add 21x to both sides of the equation. This will cancel out the -21x on the left side.
-21x + 3y = 6
-21x + 3y + 21x = 6 + 21x
3y = 21x + 6
Now, to get y alone, divide both sides of the equation by 3. This will cancel out the coefficient of 3 on the left side.
3y = 21x + 6
(3y)/3 = (21x + 6)/3
y = 7x + 2
There's the answer. Hope that helps! :)
Answer:
Proved
Step-by-step explanation:
Given

Required
Prove
On the right hand side, we have:

Rewrite:


Apply law of indices


Express 6 as 3.5 + 2.5

Open bracket

Proved
Answer: 2908.92435 inches.
Step-by-step explanation for shape 1: A = 2(wl + hl + hw) = 2 · (30 · 13 + 13 · 13 + 13 · 30) = 1,898 inches.
Step-by-step explanation for shape 2:
Using the formulas:
A=2AB+(a+b+c)h
AB=s(s﹣a)(s﹣b)(s﹣c)
s=a+b+c
2
Solving for A:
A=ah+bh+ch+1
2﹣a4+2(ab)2+2(ac)2﹣b4+2(bc)2﹣c4=9·30+13·30+9·30+1
2·﹣94+2·(9·13)2+2·(9·9)2﹣134+2·(13·9)2﹣94≈1010.92435
Step-by-step explanation for total volume: 2908.92435 inches.
Compute the volume of
:

Integrate
over
:

So the average value of
over
is 2/(4/3) = 3/2.