Question

1. If 8x - 7y=11 and 7x-8y=4, then what is the value of x + y?​

Answer 1

Answer:

8x-7y=11

7x-8y=4

56x-49y=77

56x-64y=32

___________

15y=45

y=45÷15

y=3

8x-7y=11

8x-7×3=11

8x-21 = 11

8x=11+21

8x=32

x=32÷8

x=4

: X + Y

: 4 + 3

= 7

Answer 2

Answer:

8x-7y=11

+

7x-8y=4

15x+y=15 it is first equation

8x-7y=11

-

7x-8y=4

x+y=7 it is second equation

from first and second equation

x=1/2

put 1/2 in second equation

y=13/2

x+y=7