2sinx|π-π/6=2sinπ-2sinπ/6=2*0-2*1/2=-1
= 25X^2 - 36 - 25X^2- 8X - 49 = - 8X - 85 = - 8*70 - 85 = - 560 - 85 = - 645
7х^2-0,35х=0
х (7х-0,35)=0
х=0. 7х-0,35=0
х= 0,35/7
х=0,05
(х-1)(х-4)(х-7)(х+2)=40
(х2-4х-х+4)(х2+2х-7х-14)=40
(х2-5х+4)(х2-5х-14)=40
х2-5х=y
(y+4)(y-14)=40
y2-10y-96=0
D= b2-4ac
D=484
t=-6
t=16
х2--5х=-6; х2-5х=16
х=2; х=3