Question

substitution method:
1)
$x + y = 14 \\ x - y = 4$
solve it

Answer 1

x+y=14
x=14-y
put in equation 2
x-y=4
14-y-y=4
14-2y=4
14-4=2y
10=2y
y=5 put valur of y in equation 1
x+y=14
x+5=14
x=9
hope its helpful