Question

Se, para todo x real, f(4x-3)=x2+x+1,entao f(5) é igual a

Answer 1

4x - 3 = 5

4x = 5 + 3

4x = 8

x = 8/4

x = 2

f(4x-3) = x² + x + 1

f(4.2-3) = 2² + 2 + 1

f(5) = 4 + 3

f(5) = 7