Помогите номер 894 Д Е

Question

Помогите номер 894 Д Е

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Answer 1

(5y-6)"2-81= (5y-6-7)*(5y-6+9)= (5y-15)*(5y+3)= 5(y-3)*(5y+3)
 1-(2x-1)"2= (1-(2x-1))*(1+(2x-1))=(1-2x+1)*(1+2x-1)=(2-2x)*2x=2(1-x)*2x= 2*2x*(1-x)= 4x(1-x)