## Precalculus (6th Edition)

Option $A$
With $x$=unknown number, then "seven times a number" = $7x$ "the difference between seven times a number and 9" = $7x-9$ while "the sum of a number and 2' = $x+2$ "five times the sum of a number and 2" = $5(x+2)$ Since "the difference between seven times a number and 9" is equal to "five times the sum of a number and 2" then, $7x-9=5(x+2)$ Therefore, the equation needed to solve the given problem is the one in Option $A$.