Question

If 7x-4y=11, 4x-7y=-22 then find the value of x-y

Answer 1

Step-by-step explanation:

Given -

7x - 4y = 11

4x - 7y = -22

To Find -

• Value of x - y

Now,

By Elimination method :-

→ [ 7x - 4y = 11 ] × 4

[ 4x - 7y = -22 ] × 7

→ 28x - 16y = 44

28x - 49y = -154

(-) (+) (+)

_______________

→ 33y = 198

→ y = 198/33

→ y = 6

Now, Substituting the value of y on 7x - 4y = 11, we get :

→ 7x - 4y = 11

→ 7x - 4×(6) = 11

→ 7x = 24 + 11

→ 7x = 35

→ x = 35/7

→ x = 5

Hence,

The value of x is 5 and y is 6

Then,

The value of x - y is

→ 5 - 6

→ -1

Answer 2

Answer:

-1

Step-by-step explanation:

eq 1: 7x=11+4y

X=11+4y/7...........(1)

eq 2: 4x=7y-22

X=7y-22/4........(2)

As eq 1=2

11+4y/7=7y-22/4

4(11+4y)=7(7y-22)

44+16y=49y-154

44+154=49y-16y

198=33y

y=198/33=6, Y=6

X=11+24/7=35/7=5, X=5

X-Y=5-6=-1