Задали примеры решить.100 1) (4x^2-y)*7y: (49x^2-y^2) - вопрос №72869301001427492227749223 от ttttrrrrtttr 30.11.2020 12:04

Question

Алгебра: Задали примеры решить.100 1) (4x^2-y)*7y: (49x^2-y^2) 2)(7x-y)*7: (49x^2-y^2) 3)(4x^2-25y^2)*(1: (2x+5y)+1: (2x-5y)) 4)(2x^2+xy-6y^2): (3y-2x)

ttttrrrrtttr · Answer

(7x-y)*7y:(49x^2-y^2) = (7x-y)*7y/49x^2-y^2 = (7x-y)*7y/(7x-y)*(7x+y) = 7y/7x+y

4x:(7y+2x)-(2x-7y):(2x+7y)= 4x/2x+7y - 2x-7y/2x+7y = 4x-(2x-7y)/2x+7y = 4x-2x+7y/2x+7y = 2x+7y/2x+7y = 1

(4x^2-25y^2)*(1:(2x+5y)+1:(2x-5y)) = (2x-5y) * (2x+5y) * (1/2x+5y + 1/ 2x-5y) = (2x-5y) * (2x+5y) * 2x-5y+2x+5y/ (2x+5y)*(2x-5y)= 4x

(2x^2+xy-6y^2)/(3y-2x)=2x^2-3xy+4xy-6y^2/3y-2x = -x(3y-2x)-2y(2x-3y-2x)/3y-2x = (3y-2x)(-x-2y)/3y-2x = -x-2y