Question

Solve each of the following systems of equations by the method of cross-multiplication:

x + 2y + 1 = 0

2x - 3y - 12 = 0

Answer 1

Method of cross multiplication

a₁x + b₁y + c₁ = 0

a₂x + b₂y + c₂ = 0

Given,

x + 2y + 1 = 0

2x - 3y - 12 = 0

⇒ x = - 21/- 7 = 3

⇒ y = 14/- 7 = - 2