3* √7 (-√7) = -3*7 = -21
-0.2*(√10)^2 + 4.3 = -2+4.3=2.3
1)16x²-24x+9-25=16x²-24x-16
2)9x²-30x+25-x²+6x+9=
=8x²-24x+34
3)a в шестой степени-a²+8a+16
1) x⁴-4x²+4=0
(x²-2)²=0
x²-2=0
x²=2
x=±√2
2) (16a²-8a+1)/(1-4a+x-4ax) = (4a-1)²/[(1-4a)(1+x)] = (1-4a)/(1+x)
(а+1)(а^2-а+1)-а^3
а^3+1^3-а^3=1^3=1