418)
2) 1/4 - x^2 = 0
x^2 = 1/4
x = +=1/2
4)
x^2 - 10x +25
Дискриминант = 100 - 100 = 0
х = 10/2 =5
419)
2)
(37+63)^2 = 100^2 = 10000
4) (85 -17) (85+17)/(85+17)^2 = 85-17)/85+17 = 68/102 = 2/3
421
x^3-y^3 = (x-y)(x^2+2xy+y^2)
c^3 + d^3 = (c+d)(c^2+2cd+d^2)
x^3+27 = (x+3)(x^2 +6x +9)
a^3-27 = (a-3) (a^2 + 6a + 3)
5 и 6 - тоже самое, что и наверху
7) p=1
b= +-25