Question

Find the solution of this system of equations -4x-y=-18 , -7x+y=-4

Answer 1

x = 2 and y = 10

Explanation:

It is given that,

-4x - y = -18 ---(1)

-7x + y= -4 ---(2)

To find the solution of equations

Step 1: Add eq(1) + eq(2)

-4x - y = -18 ---(1)

-7x + y= -4 ---(2)

-11x + 0 = -22

11x = 22

x = 22/11 = 2

Step 2: Substitute the value of x in eq (2)

-7x + y= -4 ---(2)

-7*2 + y = -4

-14 + y = -4

y = -4 + 14 = 10

Therefore x = 2 and y = 10

Answer 2

(x, y) = (2, 10)

Explanation:

Adding the two equations will eliminate the y-variable:

(-4x -y) +(-7x +y) = (-18) +(-4)

-11x = -22 . . . . . simplify

x = 2 . . . . . . . . . divide by -11

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Put this into the first equation to find y:

-4·2 -y = -18

-8 +18 = y = 10 . . . . . add 18+y

The solution is (x, y) = (2, 10).