We can find 82^2 by using (a b)^2 82^2 = (100 18)^2 = 100^2+18^2 2 × 100 × 18 =10000+324 3600 =6724 Or another shortcut method 1) Subtract the number from 100 w ...

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Byju's Answer

Standard VIII

Mathematics

Finding Square of a Number with Unit's Place 5

How to find 8...

Question

How to find $82^{2}$

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Solution

To find: $(82)^{2}$
$(82)^{2}$
$= (80 + 2)^{2}$
$= (80)^{2} + 2 (80) (2) + 2^{2}$ [Since, $(a + b)^{2} = a^{2} + 2 a b + b^{2}$ ]
$= 6400 + 320 + 4$
$= 6724$
$∴ (82)^{2} = 6724$
(OR)
$(82)^{2}$
$(100 - 18)^{2}$
$= (100)^{2} - 2 (100) (18) + (18)^{2}$ [Since, $(a - b)^{2} = a^{2} - 2 a b + b^{2}$ ]
$= 10000 - 3600 + 324$
$= 10324 - 3600$
$= 6724$
$∴ (82)^{2} = 6724$

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Similar questions

Solve

(82)^{2} - (81)^{2}

Q. Solve:

(82)^{2} - (18)^{2}

$(82)^{2} - (18)^{2} = ?$
(a) $8218$
(b) $6418$
(c) $6400$
(d) $7204$

Q. Find the value of:
(i) (82)² − (18)²
(ii) (128)² − (72)²
(iii) 197 × 203
(iv)

\frac{198 \times 198 - 102 \times 102}{96}

(v) (14.7 × 15.3)
(vi) (8.63)² − (1.37)²

Find the values of
(i) $(82)^{2} - (18)^{2}$
(ii) $(128)^{2} - (72)^{2}$
(iii) $197 \times 203$
(iv) $\frac{198 \times 198 - 102 \times 102}{96}$
(v) $(14.7 \times 15.3)$
(vi) $(8.63)^{2} - (1.37)^{2}$

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How to find 822

To find: (82)2(82)2=(80+2)2=(80)2+2(80)(2)+22 [Since, (a+b)2=a2+2ab+b2]=6400+320+4=6724∴(82)2=6724(OR)(82)2(100−18)2=(100)2−2(100)(18)+(18)2 [Since, (a−b)2=a2−2ab+b2]=10000−3600+324=10324−3600=6724∴(82)2=6724

How to find $82^{2}$