# Question #28b5c

Sep 20, 2016

x = 6

#### Explanation:

What we do is have all the x terms on the left of the equation and all numeric values on the right.

Operations done on equations must be done to both sides in order to maintain the 'balance'

subtract 7x from both sides.

$5 x \textcolor{red}{- 7 x} + 3 = \cancel{7 x} \textcolor{red}{\cancel{- 7 x}} - 9$

$\Rightarrow - 2 x + 3 = - 9$

now subtract 3 from both sides.

$- 2 x \cancel{+ 3} \textcolor{m a \ge n t a}{\cancel{- 3}} = - 9 \textcolor{m a \ge n t a}{- 3}$

$\Rightarrow - 2 x = - 12$

Now we have the x term on the left and numeric value on the right.

To solve for x divide both sides by - 2.

$\frac{\cancel{- 2} x}{\cancel{- 2}} = \frac{- 12}{- 2}$

$\Rightarrow x = 6 \text{ is the solution}$

We can do a check on the equation to ensure x = 6 is correct.

left side :$5 x + 3 = \left(5 \times 6\right) + 3 = 30 + 3 = 33$

right side: $7 x - 9 = \left(7 \times 6\right) - 9 = 42 - 9 = 33$

both sides are equal to 33 hence x = 6 is correct.