Answer
$35$
Work Step by Step
You are given the expression $5x$, in which $x$ is a variable, meaning its value could be basically anything, however the value of $x$ in this particular question is given to you;
$x=7$
So, substitute this value for $x$ into the original expression to get the answer.
$5x$ ($5x$ means $5$ multiplied by whatever value $x$ is)
$= 5\times (7)$
$= 35$