# Twice a number subtracted from 30 is the same as three times that num added to 15. How do you find the number?

Dec 10, 2016

Translate these conditions and call the number $X$

#### Explanation:

Twice the number: $2 X$
subtracted from 30: $30 - 2 X$
This is the left part of the equation

Three times that number $3 X$
added to 15: $3 X + 15$
This is the right part of the equation

So:
$30 - 2 X = 3 X + 15$
we now add $2 X$ on both sides, and subtract $15$

$30 - 15 - \cancel{2 X} + \cancel{2 X} = 3 x + 2 x + \cancel{15} - \cancel{15} \to$

$15 = 5 X \to X = \frac{15}{5} = 3$

Check:
$30 - 2 \times 3 = 3 \times 3 + 15 \to 24 = 24$ Check!