A=n^3-2n^2+2n-4= (n-2)(n2+2)
A=(n-2)(n2+2)
A is a prime number when n-2=1 or (n2+2)=1
=> n-2=1
=> n=3
Các câu hỏi tương tự
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Đọc tiếp
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Tìm stn n sao cho :
a, (a^4-2n^3+2n^2-2n+1) chi hết cho (n^4-1)
b, (n^3-n^2+2n+7) chia hết cho (n^2+1)
Find a 3-digit number, know that that number is divisible by 18 and its proportional numerals 1, 2, 3?
2) Tìm x thuộc Z , để:
a) \(n^2+2n-4⋮11\)
b)\(n^4-2n^3+2n^2-2n+1⋮n^4+1\)
c)\(n^3-n^2+2n+7⋮n^2+1\)
Tìm số nguyên n sao cho
a) (2n^3 + n^2 + 7n + 1) chia hết cho 2n-1
b)(n^3 - 2) chia hết cho n-2
c)(n^3 - 3n^2 - 3n -1) chia hết cho n^2 + n + 1
d)((n^4 - 2n^3 = 2n^2 - 2n + 1) chia hết cho n^4 - 1
e)(n^3 - n^2 + 2n + 7) chia hết cho n^2 + 1