Question

301, 305, 307, 311
помогите решить

Answer 1

#301
x³-x²-25x+25=0
x²·(x-1)-25(x-1)=0
(x²-25)·(x-1)=0
(x-5)·(x+5)·(x-1)=0
x-5=0
x+5=0
x-1=0
x=5
x=-5
x=1
#305
x·(x²-1)+7(x²-1)=0
(x+7)·(x²-1)=0
(x+7)·(x-1)·(x+1)=0
x+7=0
x-1=0
x+1-0
x=-7
x=1
x=-1