# How do you solve the following system?: 5x +3y =7, 91x +56y = 0

Jun 21, 2018

color(purple)(x = 56, y = -91

#### Explanation:

$5 x + 3 y = 7 , \text{ Eqn (1)}$

$280 x + 168 y = 392 , \text{Eqn (1) * 56}$

$91 x + 56 y = 0. \text{Eqn (2)}$

$273 x + 168 y = 0 , \text{ Eqn (2) * 3}$

$56 \cdot \text{ Eqn (1)" - 3 * " Eqn (2)}$,

$280 x - 273 x = 392$

$x = \frac{392}{7} = 56$

Substituting value of x in Eqn (1),

$280 + 3 y = 7$

$3 y = - 273 \text{ or } y = - 91$