C=2(pi)r use this equation with 9 in place of r
Let the two numbers be x and y.
x + y = 86
+
x - y = 12
_________
2x + 0 = 98
__________
2x = 98
x = 98/2
x = 49
From x + y = 86
49 + y = 86
y = 86 - 49
y = 37
The numbers are 49 and 37.
the first one is the answer to #1
and the second one is the answer to #2
Answer: 
<u>Step-by-step explanation:</u>

