math
posted by johnny .
The sum of two integers is 4. Their difference is 12. Name the integers.

x+Y=4 EQ1
xy=12 EQ2
x=y+12 EQ3
put in the first equation
x+y=4
substitute equation 3 for x
y+ (y+12)=4
2y+12=4
2y= 412
2y =16
y= 16/2
y= 8
Put the new value of y in EQ3
x= y+12
x= 8+12
x= 4
so two numbers are 4 and 8