# How do you solve 3(x+3)=4x?

Jan 29, 2017

$\textcolor{b l u e}{x = 9}$

#### Explanation:

$3 \left(x + 3\right) = 4 x$

Using distributive property to evaluate the expression in the left side of the equation,

$3 x + 9 = 4 x$

transposing $+ 9$ to the other side of the equation, by grouping all the same expression or term, it is a standard that the unknown variable must be in the left side of the equation,

Subtracting $9$ from both sides,

$3 x + 9 - 9 = 4 x - 9$

Refining the equation,

$3 x = 4 x - 9$

now we must move the $4 x$ to the left, balance it by subtracting both sides by $4 x$,

$3 x - 4 x = 4 x - 9 - 4 x$

Refining the equation again, we get,

$- x = - 9$

but, $x$, the unknown variable must be positive, therefore we need to take off it's negativity, since $- x = - 1 \left(x\right)$

$\frac{\cancel{- x}}{\cancel{- 1}} = \frac{- 9}{-} 1$

$\textcolor{b l u e}{x = 9}$