Question

Упростите выражения а) (2а+3х)(5а-х)-(а+х)(10а-3х) б)(7х+1)(х-5)+(3х-2)(2х+7) в) -0,1х(2х^2+6)(5-4х^2)

Answer 1

$(2a+3x)(5a-x)-(a+x)(10a-3x) = \\ 10a^{2}+15ax-2ax-3x^{2}-10a^{2}-10ax+3ax+3x^{2} = 6ax$

$(7x+1)(x-5)+(3x-2)(2x+7) = \\ 7x^{2}+x-35x-5+6x^{2}-4x+21x-14 = 13x^{2}-17x-19$

$-0,1x(2x^2+6)(5-4x^2) = \\ -0,1x(10x^{2}+30-8x^{4}-24x^{2}) = 0,8x^{5}+1,4x^{3}-3x$