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Solve the systems of equations by substituting
7) -4x+y=6
-5x-y=21

Solve the systems of equations by substituting 7) -4x+y=6 -5x-y=21-example-1

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We can use substitution to solve this system of equations. We will solve for y in one of the equations and then substitute that expression for y in the other equation. Here's how:

From the first equation, we can solve for y to get y = 4x + 6.

Now we can substitute 4x + 6 for y in the second equation and solve for x:

-5x - (4x + 6) = 21

-5x - 4x - 6 = 21

-9x = 27

x = -3

Now that we have x, we can substitute -3 back into one of the equations and solve for y:

-4(-3) + y = 6

12 + y = 6

y = -6

Therefore, the solution to the system of equations is x = -3 and y = -6.
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