Question

dada a funcao f: R -->R, f(x)=3x+6, calcule:
a)f(-5)
b)f(2/3)

Answer 1

$f(-5)=3x+6 \\ \\ f(-5)=3.(-5)+6 \\ \\ f(-5) = -15+6 \\ \\ f(-5)=-9 \\ \\ ----- \\ \\ f(\frac{2}{3})=3x+6 \\ \\ f(\frac{2}{3})=3.(\frac{2}{3})+6 \\ \\ f(\frac{2}{3})=\frac{6}{3}+6 \\ \\ f(\frac{2}{3})=2+6 \\ \\ f(\frac{2}{3})=8$