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How do you solve the following system of equations? $9 c + 2 d = 54, c + 2 d = 6 ?$ $9c + 2d = 54, c + 2d = 6?$

1 Answer

Nov 7, 2015

d=0
c=6

Explanation:

9c + 2d =54 → equation 1
c + 2d =6 → equation 2

By using substitution,

c + 2d =6
c =6-2d into equation 1

9(6-2d)=54
54-18d=54
-18d=54-54
-18d=0
d=0

Substitute d=0 into c=6-2d

c=6-2(0)
c=6

So, c=6 and d=0

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