Using x and y as the numbers
x+y=25 -------#1
x-y=9 -------#2
Using addition of #1 and #2
x+y+x-y= 25+9
2x+0y=34
2x=34
x=17
Using the value of x and plugging said value into #1 or #2, we can find y
x=17
x+y=25
17+y=25
y=8
OR
x-y=9
17-y=9
-y=-8
y=8
The numbers are 8 and 17
