# The sum of two times a number and 5 is 45 what is the number?

Nov 21, 2016

20

#### Explanation:

The sum: +

Two times a number: 2x

Let $x$ be the unknown number that $2$ is being multiplied by

The sum of 2 times a number and 5:

$2 x + 5 = 45$

Perform the opposite operation on the left side of the equation by subtracting $5$ on both sides of the equation

$2 x = 40$

Isolate $x$ by performing the opposite operation, which is division of $2$, on both sides of the equation

$x = 20$

The unknown number is $20$