Answers:
4; 20; 3x² - 4x + 3; 52; 17
Explanation:
f(-1): replace x in f(x) = x² + 3 with -1: f(-1) = (-1)² + 3 = 4
f(-4) + g(-1) = (-4)² + 3 + 2(-1) + 3 = 16 + 3 - 2 + 3 = 20 (since g(x) = 2X + 3)
3f(x) - 2g(x) = 3[x² +3] - 2[2x + 3} = 3x² + 9 - 4x - 6 = 3x² - 4x + 3
f(g(2)): First, evaluate g(2). It is g(2) = 2(2) + 3 = 7. Next, use this output, 7, as the input to f(x): f(g(x)) = (7)² + 3 = 49 + 3 = 52
g(f(2)): First, evaluate f(x) at x = 2: f(2) = (2)² + 3 = 7. Next, use this 7 as the input to g(x): g(f(2)) = g(7) = 2(7) + 3 = 17