The volume equals length x width x height so multiply all of those with a calculator and you’ll get your answer hope I helped :)
U can refer to the picture that I’ve attach below
You mean -2x+5y=20 if it was that's how you do it
so if you're finding the x intercept the y will turn to 0 why because you're only looking for x their's no need for y
so it will be -2x+0=20
-2x=20 if it's multiplication then you change it to division
-2x/-2=20/-2
x=-10
Uniform because the peak is mainly in the middle, I hope I helped
