Question

Solve for x and y:
9x - 2y = 108, 3x + 7y = 105

Answer 1

The given system of equation can be written as:
9x - 2y = 108 ……(i)
3x + 7y = 105 ……(ii)
On multiplying (i) by 7 and (ii) by 2, we get:
63x + 6x = 108 × 7 + 105 × 2 

⇒ 69 x = 966

⇒ x = `966/69 = 14`

Now, substituting x = 14 in (i), we get:
9 × 14 – 2y = 108
⇒ 2y = 126 – 108

⇒ y = `18/2`=9

Hence, x = 14 and y = 9.