The solution of the equations are
5. -6
6. 1
7. 15
8. -68
How to solve the equations
The equations are solved by substitution
f(x) = 3x - 5
g(x) = 2x² + 7x + 1
5.
= 3(-6) - 5 + 17
= -18 - 5 + 17
= -6
6. g(1) - 9
= 2(1)² + 7(1) + 1 - 9
= 1
7. f(8) + g(-1)
= (3(8) - 5) + (2(-1)² + 7(-1) + 1)
= (24 - 5) + (2 - 7 + 1)
= 19 - 4
= 15
8. 12 - 2[g(3)]
= 12 - 2[2(3)² + 7(3) + 1]
= 12 - 2[18 + 21 + 1]
= -68