SOLUTION: 8m+2=17 m-4n=31 solve by substitution

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Question 610610: 8m+2=17
m-4n=31
solve by substitution
Answer by Maths68(1474) About Me  (Show Source):
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8m%2B2=17..................(1)
m-4n=31..................(2)
Take (1)
8m%2B2=17..................(1)
8m=17-2

8m=15
m=15%2F8
Substitute the value of m in (2)
m-4n=31..................(2)
15%2F8-4n=31
-4n=31-15%2F8
-4n=%28248-15%29%2F8
-4n=233%2F8
-4n%2F-4=%28233%2F8%29%281%2F%28-4%29%29
%28cross%28-4%29n%29%2Fcross%28-4%29=-233%2F32
n=-233%2F32

n=-233%2F32,m=15%2F8


Check
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Put the values of n and m in (2)
%2815%2F8%29-%284%29%28-233%2F32%29=31
%2815%2F8%29-cross%284%29%28-233%2Fcross%2832%29%29=31
%2815%2F8%29%2B%28233%2F8%29=31
%2815%2B233%29%2F8=31
cross%28248%29%2Fcross%288%29=31
31=31