SOLUTION: I was wondering how would you solve a linear system using subsitution? My teacher taught the class this in like 10 min and I'm not sure.. Can you show me to steps to answer -x+2y=-

Question 711679: I was wondering how would you solve a linear system using subsitution? My teacher taught the class this in like 10 min and I'm not sure.. Can you show me to steps to answer -x+2y=-6 and 8x+y=31 thanks!
Found 2 solutions by stanbon, lynnlo:
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
-x+2y=-6
8x+ y=31
-------------
You have a choice: solve the 1st equation for "x"
or solve the 2nd equation for "y":
-----
Solving for x you get:
x = 2y+6
----
Substitute for "x" in the 2nd equation and solve for "y":
8(2y+6)+y = 31
16y + 48 + y = 31
17y = -17
y = -1
-----------
Solve for "x" using x = 2y+6
x = 2*-1+6
x = 4
====================
Cheers,
Stan H.
====================
Answer by lynnlo(4176) (Show Source): You can put this solution on YOUR website!
-X+2Y=-6
8X+Y=3
STEP (1)MULTIPLY FIRST EQUATION BY 8
AFTER YOU MULTIPLY YOU WILL HAVE
-8X+16Y=-48
8X+Y=3
STEP (2)ADD THE TWO EQUATIONS TOGETHER TO ELIMINATE X
17Y=-45
STEP(3) FIND Y
Y=-45/17
STEP (4)SUBSTITUTE THE VALUE FOR Y INTO THE ORIGINAL EQUATION TO SOLVE X
-X+2(-45/17)=-6
X=12/17
Y=-45/17
RELATED QUESTIONS
I have been working on solving linear systems I cannot figure out where to move and... (answered by askme)
Hi, the problem i am having is with subsitution in a qudratic equation. x^2-xy=10 (1)... (answered by scott8148,mananth)
First of all, I would like to take this opportunity to thank you for taking the time to... (answered by rapaljer)
I was wondering how would you solve a problem like this: log(2x+3) =... (answered by rapaljer)
Please can someone help me why I'm very confused with what my math teacher taught and i... (answered by kevwill)
How do I make an equation from the following word problem: A teacher gets paid $5.00 to... (answered by funmath)
I am really trying to understand this math. While in class my teacher was explaining it... (answered by stanbon)
In my math class we are doing Functions right now. The specific three we are using are... (answered by venugopalramana)
Hi, I just started an Algebra class and I'm no sure how to solve this problem using... (answered by richard1234)