Question

find the product of i} (3-7a)(3+4a) ii}(5x-4y)(5x+3y) pls fast {EXPANSION lesson]

Answer 1

$\large\green{\underline{{\boxed{\textbf{your answer}}}}}$

$1)3(3 + 4a) \: - 7a(3 + 4a) \\ = 9 + 12a \: - 21a - 28a^{2} \\ = 9 - 9a - 28a^{2}$

$2)5x(5x + 3y) \: - 4y(5x + 3y) \\ = 25x^{2} + 15xy \: - 20xy - 12y { }^{2} \\ = 25x {}^{2} - 5xy - 12y {}^{2}$

hope it help you