Question

find the value of x+y if 15x+17y=21 and 17x + 15y=11​

Answer 1

The graphical solution of the equations 15x+17y=21 and

17x + 15y=11 is,

$x = - 2\\ y = 3$

Then the value of x+y

$x + y = - 2 + 3 = 1$