Question

find 30/x-y. + 28/x+y =7. 21/x+y + 21/x+y=5​

Answer 1

Answer:

See,

Substitute 1/x-y as p

and 1/x+y as q

The equations would be then

30p +28q = 7

21p + 21q = 5

Solve for p and q. You can do it, right?

After getting values of p and q,

Resubstitute,

1/x-y = p

i.e. x-y = 1/p ....(1)

1/x+y =q

i.e. x+y =1/q....(2)

You can now solve equation 1 and 2 to get x and y

mark the answer as brainliest

Answer 2

Step-by-step explanation:

see

substitute 1/x-y as A and 1/x+y as B

now,

30A + 28B =7 - 1

21A + 21B =5 - 2

multiplying 1 by 7 and 2 by 10

we get,

210A + 196B = 49 -3

210A + 210B = 50 -4

by subtracting 2 from 1

we get,

14B = 1

B = 1/ 14

now,

by 3 we get,

210A + 196(1/14) = 49

210A = 49 - 196 (1/14 )

210A = 35

A = 1/6

now,

1/x-y = A 1/x+y = B

1/x-y = 1/6. 1/x+y = 1/14

by reciprocal,

x-y=6 - 5 x+y = 14 - 6

adding 5 and 6,

2x = 20

x = 10

by 6,

10+y=14

y = 4

Pls mark my answer as branliest