Question

3- Determine o valor da f(x)= (2x+6)(2x-1) e calcule f(3) e f(8). A) 8 e10 B) 50 e 130 C) 9 e 15 D) 11 e 18 E) 30 e 165

Answer 1

Resposta:

f(x) = (2x+6)(2x-1) = 4x² - 2x + 12x - 6 ⇒ f(x) = 4x² + 10x - 6

f(3) = (2.3 + 6)(2.3 - 1)

f(3) = (6 + 6)(6 - 1)

f(3) = 12.5

f(3) = 60

f(8) = (2.8 + 6)(2.8 - 1)

f(8) = (16 + 6)(16 - 1)

f(8) = 22.15

f(8) = 330