## Introductory Algebra for College Students (7th Edition)

The number is $18$.
Let $x$ = the unknown number Then "three times a number" means $3x$ "sum of five and three times a number" means $5+3x$ Thus, the equation that represents the situation is: $5+3x=59$ Subtract $5$ on both sides of the equation to obtain: $3x=54$ Divide $3$ on both sides of the equation to obtain: $x=\dfrac{54}{3} \\x=18$