Answer:
Explanation:
Given system:
Multiply the second equation by - 4 (the opposite of the coefficient of x in the first equation) then add up the two equations, this will eliminate x and we'll solve it for y.
- 4x - 9y = - 42
- -4x - 20y = - 16 Multiplied by -4
- -9y - 20y = - 42 - 16
- -29y = - 58
- y = -58 / - 29
- y = 2
Find x:
- x + 5*2 = 4
- x + 10 = 4
- x = 4 - 10
- x = - 6
Solution is: (-6, 2)