Q10 of 71 Page 68

To eliminate x, from 3x + y = 7 and —x + 2y = 2 second equation is multiplied by

Given: 3x + y = 7 ..(i)and —x + 2y = 2 …(ii)


Using elimination method,


Multiply (ii) by 3,


3x + y = 7 …(i)


– 3x + 6y = 6 …(iii)


Add (i) and (iii),


3x + y – 3x + 6y = 7 + 6


⇒ 7y = 13


Hence, x is eliminated by multiplying second equation by 3.

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