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Question
Solve the pair of linear (simultaneous) equation by the method of elimination by substitution :
y = 4x - 7
16x - 5y = 25
Solution
y = 4x - 7 ....(1)
16x - 5y = 25 ....(2)
y = 4x - 7
Putting this value of y in (2)
∴ 16x - 5 (4x - 7) = 25
∴ 16x - 20x + 35 = 25
∴ - 4x = - 10
∴ x = `5/2`
From (1)
y = `4(5/2) - 7`
⇒ y = 10 - 7
⇒ y = 3
Solution is x = `5/2` and y = 3.
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