Question

7x+4y=20__(1)
7x-4y=8___(2)​

Answer 1

7x=28

x=28/7

x=4

now put the value of x in equation 1

7×4+4y=20

28+4y=20

4y=20-28

4y=-8

y=-8/4

y= -2

Answer 2

Answer:

7x+4y=20

x=20-4y/7

7x-4y=8

7(20-4y/7) -4y=8

20-4y-4y=8

12=8y

12/8=y

3/2=y

7x+4y=20

7x+4(3/2)=20

7x=20-6

x=14/7

x=2

hope it helps!!