Question

Solve this system of linear equations. Separate

the x- and y-values with a comma.
-2x = 8 - 6y
-15x = 21 - 6y

Answer 1

(-1,1)

Explanation:

-2x = 8 -6y *

-15x = 21 - 6y

Solve for -6y:

-6y = -8 - 2x *

-15x = 21 - 6y

Substitute the given value of 6y into second equation, you get:

-15x = 21 -8 - 2x

Solving this equation for x gets you:

x = -1

Substitute this value (x = -1) into the equation (-6y = -8 - 2x):

-6y = -8 - 2x (-1)

This provides y:

y = 1

Answer 2

Your solution is (-1, 1).

Explanation:

-2x = 8 - 6y

-15x = 21 - 6y

Let's solve this through elimination.

Right away I can see that our y-values are the same. We want to eliminate one variable at a time, so let's make one of the -6y's a positive by multiplying each term in the equation by -1.

-15x = 21 - 6y

-1(-15x = 21 - 6y)

15x = -21 + 6y

Now we have a new equation in our system.

-2x = 8 - 6y

15x = -21 + 6y

Now, eliminate by performing each action given by the terms.

-2x = 8 - 6y

15x = -21 + 6y

___________

13x = -13

Divide both sides by 13 to isolate x.

x = -1

Now that we know x, plug it back into one of the original equations to find y.

-2x = 8 - 6y

-2(-1) = 8 - 6y

Multiply.

2 = 8 - 6y

Subtract 8 from both sides.

-6 = -6y

Divide both sides by -6.

y = 1

Your solution is (-1, 1).

Check your answer by plugging both values into one of the original equations.

-15x = 21 - 6y

-15(-1) = 21 - 6(1)

Multiply.

15 = 21 - 6

Add 6 to both sides.

15 = 15

Your answer is correct.

Hope this helps!