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

Question

Solve each of the following systems of equations by using the method of cross multiplication: x + 2y + 1 = 0, 2x – 3y – 12 = 0.

Philoid · Accepted Answer

We have,

x + 2y + 1 = 0 …(i)

2x – 3y – 12 = 0 …(ii)

From equation (i), we get a₁ = 1, b₁ = 2 and c₁ = 1

And from equation (ii), we get a₂ = 2, b₂ = - 3 and c₂ = - 12

Using cross multiplication,

⇒

⇒ and

⇒ x = 3 and y = - 2

Thus, x = 3, y = - 2