8m³+27=(2m)³+3³=(2m+3)(4m²-6m+9)
6m²+13m+6
D=13²-4*6*6=169-144=25
√D=5
m₁=(-13-5)/12=-18/12=-3/2
m₂=(-13+5)/12=-8/12=-2/3
6m²+13m+6=6(m+3/2)(m+2/3)=(2m+3)(3m+2)
A(3b-1)-b(a-3)-2(ab-a+b) = 3ab-a-ab+3b-2ab+2a-2b =a+b
Y^2 - a^2 - 5y^2 + a^2 = y^2 - 5y^2 = - 4 у в квадрате (-4y^2)