Ответы: 1
Наташа Гусева
2017-12-08 12:49
1) (2+x)^2= 4+4х+х=х+4х+4; 2) (4x-1)^2=(4х)-2*4х*1+1=16х-8х+1; 3) (2x+3y)^2=(2х)+2*2х*3у+(3у)=4х+12ху+9у; 4) (x^2-8x)^2=(х)-2х*8х+(8х)=х^4-16х+64х; 5)x^2+4x+4=(х+2); 6)25x^2-10xy+y^2=(5х-у); 7) (5x+2)^2-20x=25х+20х+4-20х=25х+4; 8) 27x^2-3(3x-1)^2=3(9х-(3х-1))=3(3х-(3х-1))*(3х+(3х-1))=3(3х-3х+1)*(3х+3х-1)=3*1(6х-1)=3(6х-1).