q=-5/1=-5
S<u />5=b1(1-q^n)/1-q=1(1-(-5)^5)/1+5=3126/6=521
Второй
x^2-6x>0
x(x-6)>0
x>0
x>6
1)2^5=64=>64:8=8
2)3.5-5.5=-2
3)-2^2=4
4)8+4=12
№1
а)5b(5a-2b)
б)6x^3(4+1)=6x^3*5=30x^3
№2
а)a^2-3a-5a+15=a^2-8a+15.
б)6p^2+12pc-12p+24c
№3
а)(x-y)(x+a)
б)a(2+c)-b(2+c)=(2+c)(a-b)
в)a(3-c)+c(c-3)=a(3-c)-c(3-c)=(3-c)(a-c)
№4
8x^2--8x^2+2x-12x+3=-10x+3
при x=-0.4 -10*(-0.4)+3=4+3=7