# How do you solve -14= -20y - 7  and 10y + 4 = 2x?

Nov 29, 2015

#### Answer:

$\left(x , y\right) = \left(\frac{15}{4} , \frac{7}{20}\right)$

#### Explanation:

Given:
[1]$\textcolor{w h i t e}{\text{XXX}} - 14 = - 20 y - 7$
[2]$\textcolor{w h i t e}{\text{XXX}} 10 y + 4 = 2 x$

Re-arranging [1] to solve for $y$
[3]$\textcolor{w h i t e}{\text{XXX}} 20 y = 7$
[4]$\textcolor{w h i t e}{\text{XXX}} y = \frac{7}{20}$

Substituting $\frac{7}{20}$ (from [4]) for $y$ in [2]
[5]$\textcolor{w h i t e}{\text{XXX}} 10 \cdot \left(\frac{7}{20}\right) + 4 = 2 x$

[6]$\textcolor{w h i t e}{\text{XXX}} \frac{7}{2} + \frac{8}{2} = 2 x$

[7]$\textcolor{w h i t e}{\text{XXX}} x = \frac{15}{4}$