How do you solve x plus y equals 10 and y equals x plus 8?

Answer 1

If x + y = 10 and y = x + 8

Substitute y = x + 8 into x + y = 10

Which gives; x + x + 8 = 10

So; 2x + 8 = 10

( - 8 from both sides); 2x=2

So: x =1. Substitute back into y = x + 8

And therefore y = 1 + 8 ; y=9