Question

5.1 multiply by 4. 9​

Answer 1

Answer:

20.9

Step-by-step explanation:

5.1x4.9

9x1=9

5x4=20

20. 9

Answer 2

Answer:

There are 2 ways to solve this :

Normal Multiplication Method :

When you normally multiply 5.1 by 4.9, you get 24.99

Algebraic Identities Method :

5.1 = 5 + 0.1

4.9 = 5 - 0.1

(a+b)(a-b) = a² - b² is a famous algebraic identity

Here, 5 is a and 0.1 is b

So, (5+0.1)(5-0.1) = 5² - 0.1²

= 25 - 0.01 = 24.99