MyQuestionIcon

1

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Expansion of (x^2 - y^2)

6. EVALUTATE ...

Question

6. EVALUTATE USING IDENTITY

i. 992

ii.101 × 99

iii. 103 × 107

Open in App

Solution

$(1) . {(99)}^{2} = {(100 - 1)}^{2} = {(100)}^{2} - 2 (100) (1) + {(1)}^{2} = 10000 - 200 + 1 [as, {(a - b)}^{2} = a^{2} + b^{2} - 2 a b] = 10001 - 200 = 9801 (2) . 101 \times 99 = (100 + 1) (100 - 1) = {(100)}^{2} - {(1)}^{2} [a s (a + b) (a - b) = a^{2} - b^{2}] = 10000 - 1 = 9999 (3) . 103 \times 107 = (100 + 3) (100 + 7) = {(100)}^{2} + (3 + 7) 100 + 3 \times 7 [a s, (x + a) (x + b) = x^{2} + (a + b) x + a b] = 10000 + 1000 + 21 = 11021$

Suggest Corrections

thumbs-up

1

Similar questions

Q. Evaluate the following using the suitable identity.
(i)

99^{3}

1001^{2}

105^{3}

105 \times 108

91 \times 106

107^{3}

Q. Using identities, evaluate

99^{2}

Q. Using suitable identities evaluate:

99^{2}

Q. Evaluate each of the following using suitable identities :

{(103)}^{3}

{(99)}^{3}

Q. Question 6(ii)
Using identities, evaluate:

99^{2}

View More

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

x^2 - y^2

MATHEMATICS

Watch in App

explore_more_icon

Explore more

Expansion of (x^2 - y^2)

Standard VIII Mathematics

Join BYJU'S Learning Program

CrossIcon