Question 821241
the digits of a two-digit number
a & b
:
 have a sum of 7
a + b = 7
:
and a difference of 5
a - b = 5
:
Use elimination here
a + b = 7
a - b = 5
---------- adding eliminates b, find a
2a = 12
a = 12/2
a = 6
the obviously,
b = 1
:
61 is the number