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Question
Solve the following simultaneous equation.
x - 2y = -1 ; 2x - y = 7
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Solution
x - 2y = -1 ...(I)
2x - y = 7 ...(II)
Multiply (I) with 2,
2x - 4y = -2 ....(III)
Subtracting (III) from (II)
2x - y = 7
2x - 4y = -2
- + +
3y = 9
∴ y = 3
Putting the value of y in (I) we get,
∴ x - 2y = -1
⇒ x - 2 × 3 = -1
⇒ x - 6 = -1
⇒ x = -1 + 6
⇒ x = 5
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