Question

what are the coordinates of the point of intersection of the lines
$x + 3y = 7$
&
$2x + y = - 1$
​

Answer 1

x+3y=7
x=7-3y….i

2x+y=-1
2(7-3y)+y=-1
14-6y+y=-1
-5y=-1-14
-5y=-15
y=3

x=7-3y
x=7-(3*3)
x=7-9
x=-2