1)X=0
2)X+2=0
X=-2
3)X-0,2=0
x=0,2
2х + 4 * ( Х + 3 ) = 12
2х + 4х + 12 = 12
7х = 12 - 12
7х = 0
Х = 0
2x^2-x-1=0
D=b^2-4ac
D=(-1)^2-4*2*(-1)=1+8=9
√D=√9=3
x1=-b<em><u /></em><em><u />+</em>√D/2a
x1=1+3/4=1
x2=-b-√D/2a
x2=1-3/4=-0,5
а²+2аb/а+b+b²/а+b=а²+2аb+b²/а+b=(а+b)²/а+b=а+b
Х⁴-2х²+1=(х²-1)²
4-20с+25с²=2²-20с+(5с)²=(2-5с²)²