Question

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

Answer 1

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

Explanation:

`5x + 3y = 7, " Eqn (1)"`

`280x + 168y = 392, "Eqn (1) * 56"`

`91x + 56y = 0. "Eqn (2)"`

`273x + 168y = 0, " Eqn (2) * 3"`

`56 * " Eqn (1)" - 3 * " Eqn (2)"`,

`280x - 273x = 392`

`x = 392/7 = 56`

Substituting value of x in Eqn (1),

`280 + 3y = 7`

`3y = -273 " or " y = -91`