Question

Solve the system by using the addition (elimination) method.

−7 x +2 y =18
−2x −7 y = 96


(x ,y)=

Answer 1

Answer −

• (x,y) = (-6, -12)

Given equation −

−7 x +2 y =18.......(1)

−2x −7 y = 96......(2)

Multiply equation (1) by 7 and equation (2) by 2.

7(−7 x +2 y = 18)

2(−2x −7 y = 96)

On multiplying we get,

-49 +14y = 126

-4x - 14y = 192

[adding both equations]

-53 x = 318

x = 318/-53

x = -6

Now let's substitute the value of x in equation (1) to get the value of y .

−7x + 2y =18.......(i)

Substitute [x = -6]

-7(-6) + 2y = 18

42 + 2y = 18

2y = 18 - 42

2y = -24

y = -24/2

y = -12

So, x = -6 and y = -12

Required answer : (x,y) = (-6, -12)