IMathAS-libretexts

For the linear function $\displaystyle {y}={7}{x}+{9}$ , when $\displaystyle {x}$ increases by 25, how does $\displaystyle {y}$ change?

$\displaystyle {y}$ increases by 175
It depends on how big $\displaystyle {x}$ is.

$\displaystyle {y}$ increases by 225
$\displaystyle {y}$ increases by 184

$\displaystyle {y}$ gets 25 times bigger