Cosa=√(1-sin²a)=√(1-19/100)=√(81/100)=9/10
1) = (12y - z^3)(12y+z^3)
2) = x(16x^2 - y^2) = x(4x-y)(4x+y)
x=1-y
(1-y)^2-2y^2+(1-y)y-(1-y)-y+3=0
1-2y+y^2-2y^2+y-y^2-1+y-y+3=0
-2y^2-y+3=0
2y^2+y-3=0
y1=1
y2=-3/2
x1=0
x2=2.5
2√60 = √4*√60 = <span>√240
</span> 6√7 = √36*√7 = <span>√252 больше.</span>