I need help with the last two !!!

Step-by-step explanation:
G(x) = - x^2 + 10x
a + G(a) = a - a^2 + 10a = - a^2 + 11a or 11a - a^2 or a(11 - a)
1/G(a) = 1/(10a - a^2) = 1/a(10 - a)