Question

Two functions are given ; f(x) = x^2+2x-1 and g(x) =5x+3 . Find the value of x if f(x) = g(x). . Also find f(-4) and g(9

Answer 1

Answer:

Explanation:

Find x:

f(x) = g(x)

x^2+2x-1 = 5x+3
x^2+2x-5x-1-3 = 0
x^2-3x-4 = 0
(x-4)(x+1) = 0
=> x-4 = 0 => x = 4
=> x+1 = 0 => x = -1

Find f(-4):

(-4)^2 + 2(-4) - 1
= 16 - 8 - 1
= 7

Find g(9):

5(9) + 3
= 45 + 3
= 48