Question

Упростите выражения а) -3х(2-х)+(3х+1)(х-2) б)3(2х-1)^2+12х в)(х+3)^2-(х-2)(х+2).

Answer 1

A)-6x+3x^2+3x^2-6x+x-2=0
6x^2-11x-2=0
D=121-4•6•(-2)=121+48=169
X1=(11-13)/2=-1
X2=(11+13)/2=12
Б)3(2x-1)^2+12x
3(4x^2-4x+1)+12x=0
12x^2-12x+3+12x=0
12x^2+3=0
3(4x^2+1)=0
1)4x^2+1=0
4x^2=-1
В) (x+3)^2-(x-2)(x+2)=0
x^2+6x+9-x^2-4=0
6x=-5
x=-5/6