Question

Find 51* 49 USING MENTAL MATH'

Answer 1

I used mental math and it took a long time, but I got the answer of 2,499.

Answer 2

Answer:

The value of given expression is 2499.

Step-by-step explanation:

The given expression is

$51\cdot 49$

This expression can be written as

$(50+1)\cdot (50-1)$

Using the property of algebraic expression we get

$(50+1)\cdot (50-1)=(50)^2-1^2$          $[\because (a-b)(a+b)=a^2-b^2]$

$(50+1)\cdot (50-1)=2500-1$

$(50+1)\cdot (50-1)=2499$

Therefore the value of given expression is 2499.