SOLUTION: what are the steps when solving an equation using substitution

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Question 117668: what are the steps when solving an equation using substitution
Answer by MathLover1(20850) About Me  (Show Source):
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Steps to solve a system of equations by the substitution method:
In general, if you solve a system of equations and the result is a true statement, such as -+8+=+-8, the system has+infinitely many solutions; if the result is a false statement, such as -+5+=+7, the system has no+solution.
We will start with an example to show the steps in solving a system of equations by the substitution method:
Use substitution to solve the system of equations #1-> +x+%2B+y+=+1 and #2-> 2x+%2B+y+=+-+1.
Step 1:
Solve one of the equations for +x or y. Let it be: solve for x from equation #1. since the coefficient of x is 1.
x+%2B+y+=+1
x+=+1-+y+
Step 2:
Substitute this value into the other equation. Use the #2.equation.
2x+%2B+y+=+-+1……………………. use the #2. equation.
2%281+-+y%29+%2B+y+=+-1……………..substitute 1+%96+y for x
2+-+2y+%2B+y+=+-1…………………….. distribute
Step 3:
Solve this equation.
2+-+2y+%2B+y+=+-1………………………….. solve for y
-y+=+-3 ……………………..divide both sides by -1
y+=+3
Step 4:
Find the value of the other variable using substitution into either equation.
x+%2B+y+=+1 ………. use the #1. equation
x+%2B+3+=+1………………substitute 3 for y
x+=+-2…………………….solution for x
The solution to the system is:
(x,y) = (-2,3)
Check: Substitute -2 for x and 3 for y in each of the original equations and check for true statements.