Evaluate:
(6 - xy) (6 + xy)
8 Likes
Using the formula
[∵ (x + y)(x - y) = x2 - y2]
= 62 - (xy)2
= 36 - x2y2
Hence, (6 - xy) (6 + xy) = 36 - x2y2
Answered By
4 Likes
(3x - 4y) (3x + 4y) (9x2 + 16y2)
Use the formula: (a + b) (a - b) = a2 - b2 to evaluate:
(i) 21 x 19
(ii) 33 x 27
(iii) 103 x 97
(iv) 9.8 x 10.2
(v) 7.7 x 8.3