how do i solve the linear system using substitution for 4x -y = 5

4x + 4y = -4

show all steps. thank you

how do i solve the linear system using substitution for 4x -y = 5

4x + 4y = -4

show all steps. thank you

Tutors, please sign in to answer this question.

Spokane, WA

4x + 4y = -4

Divide both sides by 4:

x + y = -1

Subtract y from both sides:

x = -y - 1

This (-y -1) is the value of x you can use for substitution.

The second equation was:

4x - y = 5

Now, substitute (-y -1) for x:

4(-y -1) - y = 5

Remove the parentheses:

-4y -4 -y = 5

-5y -4 = 5

Add 4 to both sides:

-5y = 9

Divide both sides by -5:

y = -9/5

Plug this value for y back into either of the original equations and solve for x:

4x + 4y = -4

Divide both sides by 4:

x + y = -1

Divide both sides by 4:

x + y = -1

x + -9/5 = -1

Add 9/5 to both sides:

x = -1 + 9/5

x = 4/5

Mark D.

Quantitative research SPECIALIST with academic/professional experience

New York, NY

5.0
(148 ratings)

John P.

Tutor of math and physics, recent college graduate

Short Hills, NJ

5.0
(21 ratings)

- Math Help 5396
- Algebra 5026
- Math Word Problem 4435
- Calculus 2188
- Word Problem 5060
- Algebra 2 3444
- Algebra 1 4034
- Math Problem 1010
- Math Help For College 1389
- Math Equations 956