Question

Dada a função f(x) = ax - 2, determine o valor de “a” para que se tenha f(4) = 30. a) 4
b) 5
c) 9
d) 12​

Answer 1

$\small\boxed{\begin{array}{l}\sf f(x)=ax-2\\\sf f(4)=a\cdot4-2\\\sf 4a-2=30\\\sf 4a=30+2\\\sf 4a=32\\\sf a=\dfrac{32}{4}\\\sf a=8\\\underline{\rm prova~real\!:}\\\sf f(x)=8x-2\\\sf se~x=4~temos\!:\\\sf f(4)=8\cdot4-2\\\sf f(4)=32-2\\\sf f(4)=30\longrightarrow dado~que~foi~fornecido~no~exerc\acute icio. \\\tt revise~o~gabarito. \end{array}}$