Question

If 8x - 7y = 11 and 7x - 8y = 4 the what is the value of x + y​

Answer 1

Answer:

8x-7y=11

7x-8y=4

multiply eq 1 by 7 and eq 2 by 8 we get

56x-49y=77

56x-64y=32

subtract

15y=45

y=3

put in eq 1 we get

8x-21=11

8x=11+21

8x=32

x=4

x+y=

3+4

=7