cho a bang 2^2+2^3+...+2^20 chung minh rang A+4 khong phai la so chinh phuong
cho A=1+1919+93199+19931999 chung minh rang A k phai la so chinh phuong
a) cho A = 1+3+5+7+...+(2n+1) Voi n thuoc N
chung to rang A la so chinh phuong
b)B=2+4+6+8+...+2n voi n thuocN
so B co phai la so chinh phuong ko
cho A = 2 + 22 + 23 + ... + 220 . chung minh rang A + 4 khong phai la so chinh phuong
cho A=30+31+32+33+....+330 chung minh rang tong A ko phai la so chinh phuong
\(A=1+3^1+3^2+3^3+...+3^{30}\)
tim chu so tan cung cua A va chung minh rang A ko phai la so chinh phuong
cho A=1+3+32+33+....+330 chung minh A k phai la so chinh phuong
hay chung minh rang A la so chinh phuong biet rang :A =1^3 + 2^3 + 3^3 + 4^3
cho A=1+3+32+33+....+330 chung minh A k phai la so chinh phuong cho minh cach giai nha
