Решите пожалуйста) 1) (2+x)^2= 2) (4x-1)^2 3) (2x+3y)^2 4) (x^2-8x)^2 5)x^2+4x+4...

Question

Решите пожалуйста)
1) (2+x)^2=
2) (4x-1)^2
3) (2x+3y)^2
4) (x^2-8x)^2
5)x^2+4x+4
6)25x^2-10xy+y^2
7) (5x+2)^2-20x
8) 27x^2-3(3x-1)^2

Answer 1

1) (2+x)^2= 4+4х+х²=х²+4х+4;
2) (4x-1)^2=(4х)²-2*4х*1+1²=16х²-8х+1;
3) (2x+3y)^2=(2х)²+2*2х*3у+(3у)²=4х²+12ху+9у²;
4) (x^2-8x)^2=(х²)²-2х²*8х+(8х)²=х^4-16х³+64х²;
5)x^2+4x+4=(х+2)²;
6)25x^2-10xy+y^2=(5х-у)²;
7) (5x+2)^2-20x=25х²+20х+4-20х=25х²+4;
8) 27x^2-3(3x-1)^2=3(9х²-(3х-1)²)=3(3х-(3х-1))*(3х+(3х-1))=3(3х-3х+1)*(3х+3х-1)=3*1(6х-1)=3(6х-1).