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प्रश्न
Solve the following pair of linear equations:
3x − 5y = 4
2y + 7 = 9x
उत्तर
Given,
3x − 5y = 4 ...........(i)
2y + 7 = 9x .............(ii)
From (ii), x =`(2"y" +7)/9` ...............(iii)
substitute x = `(2"y" +7)/9` in (i), then
`3((2"y"+7)/9)-5"y" =4`
⇒ `(2"y"+7)/3 - 5"y" = 4`
⇒ `(2"y"+7-15"y")/3 = 4`
⇒ 7 - 13y = 12
⇒ `"y" = - 5/13`
Put `"y" = - 5/13` in (iii), then
`"x" = (2(-5/13)+7)/9 = (-10+91)/(9xx13)`
⇒ x = `9/13`
Hence, x = `9/13` and y=`-5/13` is the solution for the given pair of linear equations.
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