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Question
By equating coefficients of variables, solve the following equation.
x − 2y = −10 ; 3x − 5y = −12
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Solution
x − 2y = −10 ...(I)
3x − 5y = −12 ...(II)
Multiply (I) with 3
3x − 6y = −30 ...(III)
Subtracting (II) from (III) we get,
3x − 6y = −30
3x − 5y = −12
- + +
−y = −18
⇒ y = 18
Putting the value of y in (I) we get,
∴ x − 2y = −10
⇒ x − 2 × 18 = −10
⇒ x = −10 + 36 = 26
Thus, x = 26, y = 18
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