The sum of both expressions a + b and a - b is 2a
The difference of a + b and a - b is 2b
Solution:
Given expression is: a + b and a - b
To find: sum and the difference of expressions
Sum means we have to add both expressions and we use the symbol "+"
In mathematics, sum can be defined as the result or answer we get on adding two or more numbers or terms or expressions
Sum of a + b and a - b
Sum = a + b + (a - b)
On removing the brackets,
Sum = a + b + a - b
b and -b gets cancel each other
Sum = a + a = 2a
Thus the sum of both expressions is 2a
Difference of a + b and a - b
Difference means we have to subtract the expression a + b and a - b and we use the symbol "-"
Difference = a + b - (a - b)
On removing the brackets,
There are two simple rules to remember: When you multiply a negative number by a positive number then the product is always negative. When you multiply two negative numbers or two positive numbers then the product is always positive.
Difference = a + b - a + b
a and -a gets cancel each other
Difference = 2b
Thus the difference of both expressions is 2b
