Question

Solve the following pair of linear (simultaneous) equation using method of elimination by substitution :
2x - 3y + 6 = 0
2x + 3y - 18 = 0

Answer 1

2x - 3y + 6 = 0
⇒ 2x = 3y - 6
⇒ x = `[ 3y - 6 ]/2`                     ...(1)
And,
2x + 3y - 18 = 0
⇒ 2`([3y - 6]/2)`+ 3y = 18          ...[From(1)]

⇒ 3y - 6 + 3y = 18
⇒ 6y = 24
⇒ y = 4
Substituting the value of y in (1), we have
x = `[ 3 xx 4 - 6]/2 = [12 - 6]/2 = 6/2 = 3`
∴ Solution is x = 3 and y = 4.