Using the formula a-b2-a2-2 a b-b2- evaluate-i 1962ii 6892iii 8912

(i) 1962=200 42=2002 2200 #215;4+42=40000 1600+16=38416 (ii) 6892=700 112=7002 2700 #215;11+112=490000 15400+121=474721 (iii) 8912=900 92=9002 2900 #215 ...

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

Byju's Answer

Standard VIII

Mathematics

Distributive Property of Rational Numbers

Using the for...

Question

Using the formula (a − b)² = (a² − 2ab + b²), evaluate:
(i) (196)²
(ii) (689)²
(iii) (891)²

Open in App

Solution

(i) ${(196)}^{2} = {(200 - 4)}^{2} = 200^{2} - 2 (200 \times 4) + 4^{2} = 40000 - 1600 + 16 = 38416$

(ii) ${(689)}^{2} = {(700 - 11)}^{2} = 700^{2} - 2 (700 \times 11) + 11^{2} = 490000 - 15400 + 121 = 474721$

(iii) ${(891)}^{2} = {(900 - 9)}^{2} = 900^{2} - 2 (900 \times 9) + 9^{2} = 810000 - 16200 + 81 = 793881$

Suggest Corrections

Similar questions

Q. Using the formula (a + b)² = (a² + 2ab + b²), evaluate:
(i) (310)²
(ii) (508)²
(iii) (630)²

Q. Find the square of 32 by using the formula

(a + b)^{2} = a^{2} + 2 a b + b^{2}

Find the squares of the following numbers using the formula.

(a + b)² = a² + 2ab + b²

Which of the following is correct?
a) $(a - b)^{2} = a^{2} + 2 a b - b^{2}$
b) $(a - b)^{2} = a^{2} - 2 a b + b^{2}$
c) $(a - b)^{2} = a^{2} - b^{2}$
d) $(a + b)^{2} = a^{2} + 2 a b - b^{2}$

Q. Question 3

Which of the following is correct?
a)

(a - b)^{2} = a^{2} + 2 a b - b^{2}

(a - b)^{2} = a^{2} - 2 a b + b^{2}

(a - b)^{2} = a^{2} - b^{2}

(a + b)^{2} = a^{2} + 2 a b - b^{2}

Join BYJU'S Learning Program

Using the formula (a − b)2 = (a2 − 2ab + b2), evaluate: (i) (196)2 (ii) (689)2 (iii) (891)2

(i) 1962=200-42=2002-2200×4+42=40000-1600+16=38416 (ii) 6892=700-112=7002-2700×11+112=490000-15400+121=474721 (iii) 8912=900-92=9002-2900×9+92=810000-16200+81=793881

Using the formula (a − b)² = (a² − 2ab + b²), evaluate:
(i) (196)²
(ii) (689)²
(iii) (891)²