a * b = 30
a - b = 1
a + b = 11
take ur last 2 equations, and add them
a - b = 1
a + b = 11
--------------add
2a = 12
a = 12/2
a = 6
now its just a matter of subbing
a + b = 11
6 + b = 11
b = 11 - 6
b = 5
so a = 6 and b = 5...whose product is 30, whose difference is 1, and whose sum is 11.
