Question

4. 15x + 3y = 39
12x + 9y = 51 solve by comparison method ​

Answer 1

Answer:

$15x + 3y = 39$

Given Equation: 15x + 3y = 39 ... ( i) 12x + 9y = 51 ... ( ii)

To Find: The value of x and y.

Solution: Subtract eq.i from eq.ii, we get. -3x + 6y = 12. Now divide both the sides by -3, we get. x - 2y = -4. or, x = -4 + 2y ... ( iii) By using eq.iii in eq.i, we get. 15( -4 + 2y ) + 3y = 39. or, -60 + 30y + 3y = 39.