CBSE Class 10 Answered

Dear  Student,

1.

1/5x + 1/6y = 12 ............(1)

1/3x - 3/7y = 8.................(2)

Multiply eqn(1) by 3/7 and eqn(2) by 1/6

3/35x+1/14y = 36/7...............(3)

1/18x - 1/14y = 4/3................(4)

eqn(3)+eqn(4)

=>89/630x = 136/21

=> x =89/4080

Substituting this value in eqn(1):

y = 89/1512

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2.

2x/a + y/b = 2 ............(1)

x/a - y/b = 4................(2)

eqn(1)+eqn(2)

3x/a = 6

=>x=2a

Substitute in eqn (1)

=>y = -2b

Regards Topperlearning.