Question

15 Points! 8th grade math! Let f be the function given by f(x) = 3x + |4 − x| .

Find and simplify: f(5) + [f(−1)]^2

Answer 1

$\bf f(x)=3x+|4-x| \\\\[-0.35em] ~\dotfill\\\\ \begin{array}{llll} f(5)&\qquad +\qquad &[f(-1)]\\\\ 3(5)+|4-5|&&3(-1)+|4-(-1)|\\\\ 15+|-1|&&-3+|4+1|\\\\ 15+1&&-3+|5|\\\\ 16&&-3+5\\\\ &&2 \end{array} \\\\[-0.35em] ~\dotfill\\\\ f(5)+[f(-1)]^2\implies (16)+(2)^2\implies 16+4\implies 20$