Question

Simplified form of ( 3k + 7 ) . ( 3k - 6 ) is .......... *
(a) 9k^2 - 42
(b) 9k^2 + 3k - 42
(c) 9k^2 - 3k - 42
(d) 9k^2 + 39k - 42
Q.8 Factors of expression : 4p^2 - 25q^
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Answer 1

$( 3k + 7) \times (3k - 6) \\ \\ \implies3k(3k - 6) + 7(3k + 6) \\ \\ \implies9 {k}^{2} - 18k + 21k + 42 \\ \\ \implies9 {k}^{2} + 3k + 42$

option b) is the correct answer