SOLUTION: Use substitution to solve the linear system. x + 4y = 21 4x + 2y = 6 AND Different problem: Find the solution to the system by graphing. x + y = 6 4x - y = 7

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Question 27823: Use substitution to solve the linear system.
x + 4y = 21
4x + 2y = 6
AND Different problem:
Find the solution to the system by graphing.
x + y = 6
4x - y = 7

Answer by bmauger(101)   (Show Source): You can put this solution on YOUR website!
Subtract 4y from both sides:
Now use 21-4y to substitute for x in the second equation:

Distribute:
Rearrange:
Divide:




Problem 2:

Graphically it looks like: (2.5, 3.5) or x=2.5 & y=3.5
Checking Check.
Pretty close... close as you should expect to get finding the answer through graphing.

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