tim tat ca cac so nguyen duong n sao cho:2^n-1 chia het cho 7
tim tat ca cac so nguyen n sao cho n^2+4 chia het n+2
Tim cac so nguyen duong n sao cho\(2^n-1⋮7\)
tim tat ca cac so nguyen duong x,y thoa man : 2011x+7y=42231
tim cac cap so nguyen duong nguyen to cung nhau sao cho: (x+y)/(x^2+y^2)=7/25
tim tat ca cac so nguyen x so cho x^2+x-1 la so chinh phuong
tim tat ca cac cap so nguyen x,y sao cho2xy+x-2y=4
tim cac cap so nguyen duong nguyen to cung nhau sao cho: (x+y)/(x^2+y^2)=7/25
mk can gap lam
B1. Cho f(1)=1008,f(1)+f(2)+...+f(n)=n^2.f(n) f(n)la ham so duong
tinh f(2015)
B2 Cho cac so nguyen to q,p,r,s sao cho cac so sau deu la so nguyen to p^s+s^q,q^s+s^r,r^s+s^p
tim cac so p,q,r,s
B3 co a,b,c duong a mu 3+bmu3=c^3
so sanh a^2015+b^2015 va c^2015
