SOLUTION: if the graphs of the equations x+y=0 and 5y+7x=24 intersects at(m,n), then the value of m+n is
A) -1
B) 2
C) 1
D) 0
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Linear-equations
-> SOLUTION: if the graphs of the equations x+y=0 and 5y+7x=24 intersects at(m,n), then the value of m+n is
A) -1
B) 2
C) 1
D) 0
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Question 830232: if the graphs of the equations x+y=0 and 5y+7x=24 intersects at(m,n), then the value of m+n is
A) -1
B) 2
C) 1
D) 0 Answer by TimothyLamb(4379) (Show Source):
You can put this solution on YOUR website! ---
x+y=0
5y+7x=24
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put the system of linear equations into standard form:
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x+y=0
7x+5y=24
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copy and paste the above linear system in standard form into this matrix-method solver:
https://sooeet.com/math/system-of-linear-equations-solver.php
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solution by matrix method:
x = m = 12
y = n = -12
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answer:
m+n = 0
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now by elimination method:
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( x+y=0 ) * -7
7x+5y=24
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-7x-7y=0
7x+5y=24
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add the system:
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-2y=24
y = -12
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x+y=0
x-12=0
x = 12
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solution by elimination method:
x = m = 12
y = n = -12
---
the two methods agree !
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