Question

Solve the following pair of linear (simultaneous) equation using method of elimination by substitution:
3x + 2y =11
2x - 3y + 10 = 0

Answer 1

3x + 2y = 11
⇒ 3x = 11 - 2y
⇒ x = `[ 11 - 2y ]/3`                          ...(1)
And,
2x - 3y + 10 = 0
⇒ 2x`([ 11 - 2y ]/3) - 3y + 10` = 0

⇒ `[ 22 - 4y ]/3 - 3y` = - 10

⇒ `[ 22 - 4y - 9y ]/3` = - 10

⇒ 22 - 13y = - 30
⇒ 13y = 52
⇒ y = 4

Substituting the value of y in (1), we have

`x = [ 11 - 2(4) ]/3 = [ 11 - 8 ]/3 = 3/3 = 1`

∴ Solution is x = 1 and y = 4.