Explanation:
Example 1:
a+c=b+c then a=b
First let the value of a and b be different (not equal)
a=5
b=7
c=10
a+c=b+c
5+10=7+10
15≠17
Example 2:
Let the value a and b be equal (the same)
a=5
b=5
c=10
a+c=b+c
5+10=5+10
15=15
So when,
a+c and b+c is equal, a and b are always equal.
Hope this helps ;) ❤❤❤