SOLUTION: To Whomever can assist, Thank you! This question has to do with the substitution method. I'm not sure how to do this. x + y = 20 x = y

SOLUTION: To Whomever can assist, Thank you! This question has to do with the substitution method. I'm not sure how to do this. x + y = 20 x = y - 4

Question 60132This question is from textbook Elementary and Intermediate Algebra
: To Whomever can assist, Thank you!
This question has to do with the substitution method.
I'm not sure how to do this.
x + y = 20
x = y - 4 This question is from textbook Elementary and Intermediate Algebra

Answer by Earlsdon(6294) (Show Source): You can put this solution on YOUR website!
Solving systems of equations by substitution is just one of the ways to handle this type of problem.
The idea is to reduce the number of variables (unknowns) from (in this case) two to one by substituting one of the variables by an equivalent expression that contains the other variable. Here's how it goes:
x + y = 20
x = y - 4 Substitute this equation for x into the first equation.
(y - 4) + y = 20 Simplify and solve for y.
2y - 4 = 20 Add 4 to both sides.
2y = 24 Divide both sides by 2.
y = 12 Now substitute this equation for y into either of the two given equations and solve for x.
x + (12) = 20 Subtract 12 from both sides.
x = 8
The solution is: (8, 12)

RELATED QUESTIONS
To Whomever can assist, Thank you! This has to do with the elimination by addition... (answered by funmath)

To Whomever can assist, Thank you! I'm stuck on how to use the elimination by addition... (answered by Earlsdon)

To Whomever can assist, Thank you! Now I'm supposed to choose either the substitution... (answered by funmath,checkley71)

To Whomever can assist, Thank you! Could someone help me graph this inequality? y <... (answered by tutorcecilia)

To Whomever can assist, Thank you! I need to use either the substitution method or the... (answered by funmath)

can you assist me to solved this linear equation by graphing x+2y=5 x-y=2 how do I (answered by solver91311)

To Whomever can assist, Thank You! 56) I'm suppose to graph the solution for the... (answered by stanbon)

How do I graph the solution set of x<-7??? Thanks ALLLLLOT to whomever, helps me with... (answered by Edwin McCravy)

Solving Systems of Linear Equations by the Substitution Method. I am having a... (answered by stanbon)