How do you solve 7x - 5x - 7+ 6x - 18= 3x?

1 Answer
Aug 7, 2017

See a solution process below:

Explanation:

First, group and combine like terms on the left side of the equation:

$7 x - 5 x + 6 x - 7 - 18 = 3 x$

$\left(7 - 5 + 6\right) x + \left(- 7 - 18\right) = 3 x$

$8 x + \left(- 25\right) = 3 x$

$8 x - 25 = 3 x$

Next, add $\textcolor{red}{25}$ and subtract $\textcolor{b l u e}{3 x}$ from each side of the equation to isolate the $x$ term while keeping the equation balanced:

$- \textcolor{b l u e}{3 x} + 8 x - 25 + \textcolor{red}{25} = - \textcolor{b l u e}{3 x} + 3 x + \textcolor{red}{25}$

$\left(- \textcolor{b l u e}{3} + 8\right) x - 0 = 0 + 25$

$5 x = 25$

Now, divide each side of the equation by $\textcolor{red}{5}$ to solve for $x$ while keeping the equation balanced:

$\frac{5 x}{\textcolor{red}{5}} = \frac{25}{\textcolor{red}{5}}$

$\frac{\textcolor{red}{\cancel{\textcolor{b l a c k}{5}}} x}{\cancel{\textcolor{red}{5}}} = 5$

$x = 5$