Question 203755This question is from textbook Elementary and Intermediate Algebra
: I really need help understanding how to answer these questions using the addition method...I want to learn this!!! For some reason I am just not getting it???
12.) x-2y=-1
-x+5y=11
16.) 3x+5y=-11
x-2y=11
22.) 2x=2-y
3x+y=-1
Thank you, thank you, thank you!!!!
This question is from textbook Elementary and Intermediate Algebra
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! I really need help understanding how to answer these questions using the addition method...I want to learn this!!! For some reason I am just not getting it???
12.)
x-2y=-1
-x+5y=11
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Add the two equations to solve for "y":
3y = 10
y = 10/3
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Substitute into either of the two original equations to solve for "x":
x = 2y-1
x = 2(10/3)-1
x = 20/3 - 3/3
x = 17/3
-------------------
Ans: (17/3 , 10/3)
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16.)
3x+5y=-11
x-2y=11
---
Multiply the 2nd equation by 3 to get:
3x+4y = -11
3x-6y = 33
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Subtract the 2nd from the 1st so you can solve for "y":
10y = -44
y = -22/5
-----------
Substitute into x = 2y+11 to solve for "x":
x = 2(-22/5)+(55/5)
x = 11/5
-------
Ans: (11/5 , -22/5)
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22.)
2x=2-y
3x+y=-1
---
Rearrange:
2x + y = 2
3x + y = -1
--------
Subtract 1st from 2nd to solve for "x":
x = -3
---
Substitute into y = -2x+2 to solve for "y":
y = -2(-3)+2
y = 8
------------------
Ans: (-3 , 8)
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Cheers,
Stan H.
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