Y-b/m=x (you just move everything to the other side)
I think that one number is 77 and the other is 86. 77 + 9 is 86. 86 +77 is 163.
Answer:
^algebra^
#1). a - b=4
a=4 + b .....(equation 1)
#2) a + b=12
(4 + b) + b= 12
4 + b + b=12
4 + 2b=12
2b= 12 - 4
2b =8
b= 8:2
b=4
subtituted b in equation 1
a= 4 + b
a= 4 + 4
a=8
so, the number is 8 and 4
