Question

any 1 ko solve kar do.


full method batna please.​

Answer 1

Answer:

a)21²-20²

here we will apply a²-b²

a²-b²=(a+b)(a-b)

21²-20²=(21+20)(21-20)

=41×1

=41

hope it helps

Answer 2

(a) 21² - 20²

identity used:

a² - b² = ( a + b )( a - b )

⟹ ( 20 + 21 ) ( 21 - 20

⟹ 41 ( 1 )

⟹ 41

(b) 34² - 33²

identity used:

a² - b² = ( a + b )( a - b )

⟹ ( 34 + 33 ) ( 34 - 33 )

⟹ 67 ( 1 )

⟹ 67

(c) 95² - 94²

identity used:

a² - b² = ( a + b )( a - b )

⟹ ( 95 + 94 ) ( 95 - 94 )

⟹ 189 ( 1 )

⟹ 189

More:

Identities can help in shorten the calculations. Here we have to find the difference between two squares. So we could use the identity: a² - b² = ( a + b) ( a - b ). We could shorten our calculations even more. As we have to find the difference between square of x and square of x+ 1 . We could also take the sum of both numbers.

( x + 1 )² - x² = ( 2x + 1 )