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

Andrea R.

Ph.D. Tutor: K-9 Reading, Math, Writing, Test Prep, Special Needs

Wyckoff, NJ

5.0
(409 ratings)

Lorraine S.

Lorraine's Literacy and Learning for Life

Staten Island, NY

4.9
(480 ratings)

Wesley L.

Premier MIT Math Tutor and SHSAT/SAT/ACT Specialist

New York, NY

5.0
(228 ratings)

- Math Help 5028
- Algebra 4732
- Math Word Problem 4062
- Calculus 2086
- Word Problem 4847
- Algebra 2 3242
- Algebra 1 3853
- Math Problem 948
- Math Help For College 1339
- Math Equations 930