Can y’all help me on this I just don’t understand it’s find su and m is the midpoint

SU = 70

Step-by-step explanation:

First, we need to find the value of x. Since M is the midpoint of SU, that means that SM = MU, therefore:

x + 15 = 4x - 45

15 = 3x - 45

60 = 3x

x = 20

We know that SU = SM + MU = (x + 15) + (4x - 45) = 5x - 30 and that x = 20 so SU = 5x - 30 = 5 * 20 - 30 = 100 - 30 = 70.

i got 86 for this

hope this !

if you need an explanation just ask

your answer is b.

1,333 cubic feet  

and i know this one is right.