Answer:
Step-by-step explanation:
Instead of x substitute (x + 4) to f(x) = x² - 12
f(x + 4) = (x + 4)² - 12 use (a + b)² = a² + 2ab + b²
f(x + 4) = x² + 2(x)(4) + 4² - 12
f(x + 4) = x² + 8x + 16 - 12
f(x + 4) = x² + 8x + 4