Question

f(x)=7x+1, entao f(12)-f(9)/3 é igual a???

Answer 1

f(12) = 7.12 + 1 = 84 + 1 = 85
f(9) = 7.9 + 1 = 63 + 1 = 64
$\frac{f(12)-f(9)}{3} = \frac{85-64}{3} = \frac{21}{3} = 7$