Answer:
Step-by-step explanation:
The given system of equations is expressed as
10x + 5y = -5 - - - - - - - - - - - -1
3x - 2y = -12 - - - - - - - - - - - -2
We would eliminate x by multiplying equation 1 by 3 and equation 2 by 10. It becomes
30x + 15y = - 15 - - - - - - - - - - - -3
30x - 20y = - 120 - - - - - - - - - - - -4
Subtracting equation 4 from equation 3, it becomes
35y = 105
Dividing the left hand side and the right hand side of the equation by 35, it becomes
35y/35 = 105/35
y = 3
Substituting y = 3 into equation 1, it becomes
10x + 5 × 3 = -5
10x + 15 = - 5
Subtracting 15 from left hand side and the right hand side of the equation, it becomes
10x + 15 - 15 = - 5 - 15
10x = - 20
Dividing the left hand side and the right hand side of the equation by 10, it becomes
10x/10 = - 20/10
x = - 2
