Решение в
приложении.<span> </span>
1) (5х+2)²=25x^2+10x+4
2) (1/3а²-1/9)²=1/9 a^4-2/27 a^2+1/81
3) (х-5у)²-(2х+у)²=(x-5y-2x-y)(x-5y+2x+y)=(-x-6y)(3x-4y)
4) (4х-3)²=16x^2-24x+9
5) (1/3а²+1/5)²=1/9 a^4+1/15a^2+1/25
<span>6) (5х+у)²-(х-2у)²=(5x+y-x+2y)(5x+y+x-2y)=(4x+3y)(6x-y)</span>
sqrt(2)*cos(x)+1=0
cos(x)=-1/sqrt(2)
x=±arccos(-1/sqrt(2))+2*pi*n
x=±3*pi/4+2*pi*n
<span>68^3+17^3 = (68 + 17) * (68^2 - 68*17 + 17^2)
</span><span> 68^2 - 68*17 + 17^2 - 68*17 =
</span>= 68^2 - 2*68*17 + 17^2 =
= (68 - 17)^2 = 51^2 = 2601