Answer:
The solution to the system is S= (-2, -4).
Explanation:
Given the system
−4x+5y=−12
x−6y=22
The first step is to solve x from the first equation for example, and substitute the expression in the second equation.
1) -4x + 5 y = -12 ⇒ -4x = -12 - 5y ⇒ x = (-12 - 5y)/-4 ⇒ x = 3 + (5/4)y
2) x - 6y = 22 ⇒ (3 + (5/4)y) - 6y = 22 ⇒ 3 + (5/4)y - 6y = 22
⇒ 3 - (19/4)y = 22 ⇒ (-19/4)y = 22- 3 ⇒ y = 19/(-19/4) ⇒ y =-4.
Finally, with the value obtained for "y", you have to return to the original equations and replace it to obtain the "x" value.
-4x + 5y = -12 ⇒ -4x + 5(-4) = -12 ⇒ -4x - 20 = -12 ⇒ -4x = -12 + 20
⇒ -4x = 8 ⇒ x = 8/-4 ⇒ x = -2.
Summarizing, the solution to this system is S = (-2, -4).