Simplify the following using the formula: $(a - b) (a + b) = a^{2} - b^{2}$
(i) $(82)^{2} - (18)^{2}$
(ii) $(467)^{2} - (33)^{2}$
(iii) $(79)^{2} - (69)^{2}$

Open in App

Solution

$1) (82)^{2} - (18)^{2}$
$= (82 + 18) (82 - 18)$
$= 100 \times 64 = 6400$

$2) (467)^{2} - (33)^{2}$
$= (467 + 33) (467 - 33)$
$= 500 \times 434 = 217000$

$3) (79)^{2} - (69)^{2}$
$= (79 + 69) (79 - 69)$
$= 148 \times 10 = 1480$

Suggest Corrections

Similar questions

Simplify the following using the formula: $(a - b) (a + b) = a^{2} - b^{2} :$

$(i) (82)^{2} - (18)^{2}$ $(i i) (467)^{2} - (33)^{2}$ $(i i i) (79)^{2} - (69)^{2}$ $(i v) 197 \times 203$

$(v) 113 \times 87$ $(v i) 95 \times 105$ $(v i i) 1.8 \times 2.2$ $(v i i i) 9.8 \times 10.2$

69^{2} - 59^{2}

101^{2} - 91^{2}

1002^{2} - 998^{2}

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

101^{2} - 99^{2}

(10.3)^{2} - (9.7)^{2}

Using a²− b² = (a + b) (a − b), find

(i) 51² − 49² (ii) (1.02)² − (0.98)² (iii) 153² − 147²

(iv) 12.1² − 7.9²

Question 92 (iii)

Factorise the following using the identity $a^{2} - b^{2} = (a + b) (a - b) .$

$4 x^{2} - 49 y^{2}$

Join BYJU'S Learning Program