# How do you solve the following system?: 2x +y =7, 8x -7y = 0

Sep 3, 2016

$x = \frac{49}{22}$

$y = \frac{28}{11}$

#### Explanation:

$2 x + y = 7$ or $8 x + 4 y = 28$

$8 x - 7 y = 0$

or

$8 x = 7 y$

Plugging the value $8 x = 7 y$ in the equation

$8 x + 4 y = 28$

We get

$7 y + 4 y = 28$

or

$11 y = 28$

or

$y = \frac{28}{11}$------------------------------Ans $1$

Plugging the value $y = \frac{28}{11}$ in the equation $2 x + y = 7$

We get

$2 x + \frac{28}{11} = 7$

or

$2 x = 7 - \frac{28}{11}$

or

$x = \frac{49}{11} \times \frac{1}{2}$

or

$x = \frac{49}{22}$----------------------------------Ans $2$