SOLUTION: solve using the Solve using the substitution method -x + 6y = 54 3x + y = 9

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: solve using the Solve using the substitution method -x + 6y = 54 3x + y = 9       Log On


   

Question 466753: solve using the Solve using the substitution method
-x + 6y = 54
3x + y = 9
Found 2 solutions by stanbon, Alan3354:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
solve using the Solve using the substitution method
-x + 6y = 54
3x + y = 9
---
Multiply thru the 1st equation by 3:
-3x + 18y = 3*54
3x + y = 9
-----------------------
Add and solve for "y":
19y = 171
---
y = 9
----
Solve for "x":
3x + y = 9
3x = 0
x = 0
=================
Cheers,
Stan H.

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
solve using the Solve using the substitution method
-x + 6y = 54
3x + y = 9
------------
3x + y = 9 --> y = 9 - 3x
Sub for y in the 1st equation
---------
-x + 6y = 54
-x + 6(9-3x) = 54
-x + 54 - 18x = 54
-19x = 0
x = 0
----------
sub for x in either eqn
y = 9