Solve the System of Equations

8x + 15y = - 117

4x + 9y=-75

Write your answer as an ordered pair: (x, y)

The ordered pair value of (x, y) is (6,-11)

Solution:

Given Equations are

Let 8x + 15y = - 117 be Equation 1 and 4x + 9y=-75 be Equation 2.

Solving Equations 1 and 2 to get the value of x and y.

Multiply Equation 2 with 4.

16x + 36y = - 300

On dividing the above expression by 2, we get

8x + 18y = - 150 (Change the sign to get the value of y).

-8x - 18y = 150 - - - eqn 3

Now solving eqn 1 and eqn 3

8x + 15y = - 117

-8x - 18y = 150

By cancelling 8x and - 8x in eqn 1 and eqn 3

-3y = 33

y = - 11

Substitute the value y in Equation 2.

4x + 9 (-11) = - 75

4x - 99 = - 75

4x = - 75 + 99

4x = 24

x=6

Hence the value of x and y is (6,-11).