I cannot figure out this question. I really need help from beginning all the way to end.

Let ∫9(bottom) 12 (top) f(x) dx = 9,

∫9 (bottom)10(top) f(x) dx=8,

∫11 (bottom)12(top) f(x)dx = 1.

Find ∫10 (bottom) 11 (top) f(x)dx=

and ∫11 (bottom) 10 (top) (9 f(x)− 8)dx=