Explanation:
Given:
f(x) = x² + 3
To find:
f(a + 7),
Replace x with (a + 7) in the function f(x) = x² + 3:
→ f(a + 7) = (a + 7)²+ 3
Now,simplify by expanding the square:
→ f(a + 7) = a² + 14a + 49 + 3
→ f(a + 7) = a² + 14a + 52
Therefore, f(a + 7) = a²+ 14a + 52.