the answer is 0=0 because there is infinite solutions
All you do is solve for z. So 8z-13=7. To solve for a variable you have to do the opposite to cancel out the numbers on each side. First you add 13 over to 7 to cancel out 13 on the z side. So 8z=20 is what you have left. Then you divide 8 on both sides to cancel out 8 on the z side. what you are left with is z=2.5. Lastly you plug and check. 8(2.5) - 13 = 7, 20-13=7. And thats correct so z is 2.5.
The area of one face would he h^2.
There are 6 faces, so the total surface area would be h^2 x 6
Replace total surface area with 2.16, so you now have:
2.16 = h^2 x 6
Now we can solve for h.
Divide both sides by 6:
h^2 = 2.16/6
Take the square root of both sides:
h = √2.16/6
The answer is A.
