Question

{4x+y=7}
{2x-5y=9}
S={ }

Answer 1

4x+y=7
4x= 7-y
x= 7/4 - y/4

2x-5y=9
2*(7/4 - y/4)-5y=9
7/2 - y/2 - 5y = 9
-11y/2 = 9 - 7/2
-11y/2 = 11/2
y = -1

x= 7/4 - (-1)/4 
7/4 + 1/4 = 2