solve and check the solutions 3x + 2y = -4, x + 2y = -8

Question

3x+2y=-4

x+2y=-8

Answer 1

Substitution method :

Given  equations are

3x + 2y  = - 4 ---> (1)

 x + 2y = - 8  ---> (2)

From (2) substitute the y value in equation (1).

3x + 2(- x - 8)/2 = - 4

Combine like terms uisng distributive property.

6x - 2x - 16 = - 8

4x - 16 = - 8

Add 16 to each side.

4x  = - 8 + 16

4x  = 8

Divide each side by 4.

x = 2.

Substitute the x  value in equation (2).

y  = (- 2 - 8)/2

y  = - 5

Solution x  = 2, y  = - 5.

Check :

Substitute the x , y  values in equation (1).

3(2) + 2( - 5) = -4

6 - 10 = -4

- 4 = - 4.

So.the above solution is true.