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Question
If 17x + 15y = 11 and 15x + 17y = 21, then find the value of x − y.
Solution
The given equations are
17x + 15y = 11 ...(1)
15x + 17y = 21 ...(2)
Now, let’s subtract equation (2) from (1)
17x + 15y = 11
15x + 17y = 21
− − −
___________________
2x − 2y = −10
Dividing the above equation by 2, we get
x − y = −5.
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