Question

solve for x and y

7 x - 2y /xy = 5

and 8x + 7y / xy = 15


agr kisi ne bhi spam kiya na usski inne sare answer report krdungi tum soch bhi ni skte !! so stay away ​

Answer 1

x = 1 , y = 1

Explanation:

Given simultaneous equations:

(7x-2y)/xy = 5

=> 7x/xy - 2y/xy = 5

=> 7/y - 2/x = 5 ----(1)

and

(8x+7y)/xy = 15

=> 8x/xy + 7y/xy = 15

=> 8/y + 7/x = 15 ----(2)

Let 1/x = a , 1/y = b

Then ,

The equations becomes,

7b-2a=5 -----(3)

8b+7a=15 -----(4)

Now ,

multiply equation (3) by 7, and

equation (4) by 2, we get

49b-14a = 35 ----(5)

16b+14a=30-------(6)

Add equations (5) and (6), we

get

65b = 65

=> b = 65/65

=> b = 1

substitute b=1 in equation (3),

we get

7b - 2 = 5

=> 7b = 5+2

=> b = 7/7

=> b = 1

Therefore,

a = 1 => 1/x = 1 => x = 1

and

b=1 => 1/y = 1 => y = 1

•••••

Hope it helps sister ♡︎

Answer 2

$\huge{\red{\mathtt{\underline{Answer:}}}}$

First equation ..

$\mathtt{\frac{7x - 2y }{xy}= 5}$

$\mathtt{ \frac{7x}{xy} -\frac{2y}{xy}=5}$

$\mathtt{\frac{7}{y} - \frac{2}{x} = 5 }$ ------ ( 1 )

Second equation ..

$\mathtt{\frac{8x+7y}{xy}=15}$

$\mathtt{\frac{8x}{xy}+\frac{7y}{xy}=15}$

$\mathtt{\frac{8}{y} +\frac{7}{x}=15}$ ----- ( 2 )

• Let 1/x = a

• Let 1/y = b

So first equation becomes ..

7b - 2a = 5 ----------- ( 3 )

and second equation ..

8b + 7a = 15 ------------ ( 4 )

I am gonna solve it by elimination method..

Multiply by 7 to eqn ( 3 ) and by 2 to eqn ( 4 ) .

so ,Equation 3rd becomes ...

49b - 14a = 35 ------- ( 5 )

and fourth becomes ..

16b + 14a = 30 ----------- ( 6 )

By adding eqn ( 5 ) and ( 6 )

65b = 65

b = 1

put b in eqn ( 3 )

7 - 2a = 5

2a = 7 - 5

2a = 2

a = 1

________________________

But $\mathtt{\frac{1}{x}= a}$

$\mathtt{\frac{1}{x} = 1 }$

So , x = 1

But $\mathtt{\frac{1}{y}= b}$

$\mathtt{\frac{1}{y} = 1 }$

So , y = 1