Explanation:
5x + 4y = 58 ....1
3x + 7y = 67 ....2
....1 × 3 both sides of the equation
15x + 12y = 174 ....3
....2 × 5 both sides of the equation
15x + 35y = 335 ....4
.....4 - ......3 both sides of the equation
35y - 12y = 335 - 174
23y = 161
y = 161/23
= 7
