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29 votes
-10x-15y=25x - 5y = -9

User Jakub Siemaszko
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1 Answer

14 votes
14 votes

Given the system of equations:

-10x-15y=25...................................equation 1

x - 5y = -9.....................................equation 2

Let's solve using substitution method.

From equation 2, make x the subject:

x = -9 + 5y

Substitute (-9 + 5y) for x in equation 1:

-10(-9 + 5y) - 15y = 25

-10(-9) - 10(5y) - 15y = 25

90 - 50y - 15y = 25

90 - 65y = 25

Subtract 90 from both sides:

90 - 90 - 65y = 25 - 90

-65y = -65

Divide both sides by -66



User Levi Cole
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