Question

F(x)=4x^2+7x-18 find f(-9)

Answer 1

To find f(-9) you have to replace x = -9 into f(x) as follows:

f(x)=4x²+7x-18

f(-9) = 4(-9)² + 7(-9) - 18

f(-9) = 4(81) - 63 - 18

f(-9) = 324 - 63 - 18

f(-9) = 243