Sagot :
so assuming x=x and y=y for both equations
use elimination
multiply first equation by 7 and second equation by 2
-28x-14y=98
-20x+14y=-50
add
-28x-14=98
-20x+14y=-50 +
-48x+0y=48
-48x=48
divide both sides by 48
-x=1
multiply -1
x=-1
subsitute
-4x-2y=14
-4(-1)-2y=14
4-2y=14
subtract 4 from both sides
-2y=10
divide both sides by 2
-y=5
multiply -1
y=-5
x=-1
y=-5
use elimination
multiply first equation by 7 and second equation by 2
-28x-14y=98
-20x+14y=-50
add
-28x-14=98
-20x+14y=-50 +
-48x+0y=48
-48x=48
divide both sides by 48
-x=1
multiply -1
x=-1
subsitute
-4x-2y=14
-4(-1)-2y=14
4-2y=14
subtract 4 from both sides
-2y=10
divide both sides by 2
-y=5
multiply -1
y=-5
x=-1
y=-5
-4x - 2y = 14 ⇒ -28x - 14y = 98
-10x + 7y = -25 ⇒ 20x - 14y = 50
-48x = 48
-48 -48
x = -1
-4x - 2y = 14
-4(-1) - 2y = 14
4 - 2y = 14
- 4 - 4
-2y = 10
-2 -2
y = -5
(x, y) = (-1, -5)
-10x + 7y = -25 ⇒ 20x - 14y = 50
-48x = 48
-48 -48
x = -1
-4x - 2y = 14
-4(-1) - 2y = 14
4 - 2y = 14
- 4 - 4
-2y = 10
-2 -2
y = -5
(x, y) = (-1, -5)