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Question
Solve the pair of linear (simultaneous) equation by the method of elimination by substitution:
6x = 7y + 7
7y - x = 8
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Solution
6x = 7y + 7 ...(1)
7y - x = 8 ...(2)
7y - x = 8
∴ x = 7y - 8
Putting this value of x in (1)
6( 7y - 8 ) = 7y + 7
∴ 42y - 48 = 7y + 7
∴ 35y = 55
∴ y = `11/7`
From (2)
`x = 7(11/7) - 8`
x = 3
∴ x = 3, y = `11/7`.
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