Answer:
f(2) = -3
Explanation:
Find f(2) given f(x) = 2x^2 + 5x - 21
Since on the left side, x is replaced by 2, on the right side, x should also be replaced by 2.
f2 = 2(2)² + 5(2) - 21
2 x 2² = 2 x 4 = 8
5 x 2 = 10
8 + 10 = 18
18 - 21 = ?
-(21 - 18 = 3)
-21 + 18 = -3
f(2) = -3