Evaluate:
(3x - 4y) (3x + 4y) (9x2 + 16y2)
4 Likes
Using the formula
[∵ (x + y)(x - y) = x2 - y2]
= [(3x)2 - (4y)2] (9x2 + 16y2)
= (9x2 - 16y2) (9x2 + 16y2)
= (9x2)2 - (16y2)2
= 81x4 - 256y4
Hence, (3x - 4y) (3x + 4y) (9x2 + 16y2) = 81x4 - 256y4
Answered By
2 Likes
(a + b) (a - b) (a2 + b2)
(3 - 2x) (3 + 2x) (9 + 4x2)
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
(6 - xy) (6 + xy)