Question

Answer this question plzz*zzz question no. 4 plzzz answer in the given attachment

Answer 1

Answer:

18

Step-by-step explanation:

Given :

$\large \dfrac{4}{x}+5y=7$    and  

$\large \dfrac{3}{x}+4y=5\\\\\\\large \text{Let \dfrac{1}{x}=p }$

So now we have

4 p + 5 y = 7

Multiply by 3

12 p + 15 y = 21

12 p = 21 - 15 y ....( i )

3 p + 4 y = 5

Multiply by 4

12 p + 16 y = 20  

12 p = 20 - 16 y ....( ii )

From ( i ) and ( ii ) we have

21 - 15 y = 20 - 16 y

- 15 y + 16 y = 20 - 21

y = - 1

Put y = -1 in ( i )

12 p = 21 - 15 y

12 p = 21 + 15

12 p = 36

p = 3

put p = 3 in value of x

$\large \dfrac{1}{x}=p\\\\\\\large \dfrac{1}{3}=x\\\\\\\large x=0.33$

Now we have value of x and y

We have to find value of n

Given    n x = 4 - 2 y

putting values of x and y

$\large n x = 4 - 2 y \\\\\\ \large n \times\dfrac{1}{3} = 4 - 2\times-1 \\\\\\ \large \dfrac{n}{3}=6\\\\\\ \large n=18$

Thus we get answer n = 18.