∫[a,b]f(x)dx = -8 , ∫[b,c]f(x)dx = 11, ∫[c,d]f(x)dx = -9. So ... ∫[a,d]f(x)dx = -6.
3∫[b a]f(x)dx-5 ∫[c b]f(x)dx= 3⋅8 - 5⋅(-11) = 79
∫[d b]f(x)dx-∫[c d]f(x)dx= 9 - 11 - (-9) = 7
∫[a b]f(x)dx= -8 (see above)
∫[m b]f(x)dx+∫[n m]f(x)dx+∫[c n]f(x)dx = ∫[c b]f(x)dx = -11
∫[b a]f(x)dx+∫[b c]f(x)dx = 8 + 11 = 19
∫[d b]f(x)dx = 9 - 11 = -2
∫[b b]f(x)dx = 0