Question

Pls help me with this math equation

For F(x)=3x+4 and g(x)= x^2-3x, find g(f(x)).

Answer 1

g(f(x)) = 9x² + 15x + 4

Explanation:

Given :

⇒ f(x) = 3x + 4

⇒ g(x) = x² - 3x

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Solving :

⇒ g(f(x))

⇒ g(3x + 4) = (3x + 4)² - 3(3x + 4)

⇒ g(3x + 4) = (3x)² + 2(3x)(4) + (4)² - 9x - 12

⇒ g(3x + 4) = 9x² + 24x + 16 - 9x - 12

⇒ g(f(x)) = 9x² + 15x + 4