<span>2xy-6y^2a=<span>-2y*(3ay-x)</span></span>
<span><span>2xy-6y^2=-2y*(3y-x)</span></span>
a^3-4a=(a-2)*a*(a+2)
1)5 1/6:4 2/15=31/6 * 15/62=465/372=1 1/4
2)3 1/6-1 1/4=19/6 - 5/4=76/24 - 30/24=46/24
3)3/12:30 2/3=23/12:92/3=23/368=1/16
По теореме Виета
х1+х2=-b/12
x1*x2=-7/12
x1=0,25=1/4
x2=-7/12:1/4=-7/3
-b/12=1/4-7/3 *(-12)
b=-3+28=25
b=25
√27-√75+√243 = √(9*3) - √(25*3) + √(81*3) = 3√3 - 5√3 + 9√3 = 7√3.
7х^2 + 4х = 0
а = 7, б = 4, с = 0
D = 4^2 - 4*7*0 = 16 - 0 = 16 > 0 ( 2 корня )
х1 = - 4 + корень из 16 = (- 4 + 4) : 14 = 0
х2 = (- 4 - 4) : 14 = - " 4:7 "