Question

if the range of the function f(x)=x/4 is {28,30,32,34,36}, what is its domain?a. {112, 120, 128, 136, 144}b. {118, 122, 124, 132, 145}c. {110, 118, 122, 124, 137}d. {111, 124, 128, 132, 146}

Answer 1

$f(x)=\dfrac{x}{4}\to y=\dfrac{x}{4}\to x=4y\\\\y\in\{28;\ 30;\ 32;\ 34;\ 36\}\\\\4\cdot28=112\\4\cdot30=120\\4\cdot32=128\\4\cdot34=132\\4\cdot36=144\\\\Answer:D=\{112;\ 120;\ 128;\ 136;\ 144\}\to\fbox{a.}$