Question

Solve elimination x-2y=10 and 3x+y=-12

Answer 1

x = -2, y = -6

(-2, -6)

Explanation:

Add the equations in order to solve for the first variable. Plug this value into the other equations in order to solve for the remaining variables.

Answer 2

Answer: x = -2 and y = -6

Step-by-step explanation:

x - 2y = 10 ................... I

3x + y = - 12 ................. II

Since we are to use elimination method , you have to decide whether you want to eliminate x first or y first. Let us eliminate x first, then we have to look for a way to make sure that the x in the two equations have the same coefficient . To do that, multiply equation I by 3 and equation II by 1 i.e

3 ( x - 2y = 10 ) ........... III

1 ( 3x + y = - 12) .......... IV

expanding the bracket

3x - 6y = 30 ................ III

3x + y = - 12................. IV

Since the x are having the same coefficient , we can then eliminate by subtracting equation IV from equation III

i.e

3x - 3x - 6y - y = 30 - ( -12)

-6y - y = 30 + 12

- 7y = 42

y = 42/ -7

y = -6

You will then substitute y = -6 into either equation I or II , so, substituting into equation I , we have

x - 2 ( -6) = 10

x + 12 = 10

x = -2