Which of the following are solutions?

This is a quadratic equation. There's a shortcut (two shortcuts really) called the Shakespeare Quadratic Formula (2b or -2b) applicable when the middle term is even:

OK, our problem is

Typically we'd write but the answers here don't so we won't either.

C and D

v: l•w•h÷2.

v: 20•6•8 ÷2

v: 960÷2

v: 480

x = 25

step-by-step explanation:

a^2+b^2=c^2

7^2+24^2=c^2

49+576=625

sqrt625=25

x=25