Question

Find the square of 49 without actual multiplication
1. 1521
2. 1251
3. 1522
4. 1531
Pls help me ​

Answer 1

Step-by-step explanation:

• $\sf{ {(a-b)}^2=a^2 - 2ab + b^2}$

✴49 = 50-1

Here, a= 50 and b = 1.

Substituting the values :

$\sf{ {(49)}^2=(50)^2 -2\times50\times1 + ( 1)^2}$

$\sf{ {(49)}^2=2500 - 100 + 1}$

$\sf{ {(49)}^2=2501 - 100 }$

$\sf{\therefore{\underline{\tt{ {(49)}^2=2401 }}}}$