A³-5a²+20-4a=0. Решите пожалуиста

Question

A³-5a²+20-4a=0. Решите пожалуиста

Answer 1

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Answer 2

(a³-5a²) +4(5 -a) =0

a²(a -5) -4(a -5) =0

(a -5)(a² -4) =0

a -5 =0, a =5

a² -4 =0, (a -2)(a +2) =0

a -2 =0, a =2
a +2 =0, a= -2

ответ: a= -2, a =2, a =5