Question

Solve the following pairs of linear equations elimination
method x+y=7xy and
2x-3y + xy=0
​

Answer 1

Answer:

Hi friend, Here's the required answer:-

Let 1/ x+y = p and 1/ x-y = q.

Then the pair of linear equations in two variables is-

5p -2q = -1 ---------------(1)

15p +7q= 10. -------------(2)

Now Multiplying the equation (1) by 3.,

15p-6q= -3 ---------------(3)

Now By ELIMINATION METHOD,

Subtracting (3) from (1),

(15p+7q)- (15p-6q)= 10-(-3)

15p +7q-15p+6q = 10+3

13q= 13

q=1

Now putting value of q in (1),

5p-2(1)= -1

5p-2=-1

5p=1

p=1/5

So p= 1/x+y And q= 1/x-y

1/5= 1/x+y. 1= 1/x-y

5= x+y. 1= x-y

Adding both the equation,

x+y+x-y= 5+1

2x= 6

x= 3

Now, x+y=5

3+y=5

y=2

So , x= 3 and y=2.

Hope this helps you..