\(2a=2^3+2^4+...+2^{2021}.\)
\(\Rightarrow a=2^{2021}-4\Rightarrow a+4=2^{2021}=2.\left(2^{1010}\right)^2\)không là số chính phương
cho a=2+2^2+2^3+............+2^2015 Chung minh a ko chia het 7
a co la so chinh phuong ko vi sao
cho a bang 2^2+2^3+...+2^20 chung minh rang A+4 khong 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
a) cho A = 1 + 3 + 5 + 7 +......+(2n + 1) Voi n thuoc N
chung to rang A la so chinh phuong
b) cho B = 2 +4+6 + 8 + ....+ 2n Voi n thuocN
so B co the la chinh phuong ko
cho A=3+4+42+...+420 chung minh rang 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
chung minh rang neu a,b la tong cua2 so chinh phuong thi ab cung la tong cua 2 so chinh phuong
mn giup minh voi
cam on nhung ban nao da giup minh giai bai toan nay
Cho B=2+2^2+.....+2^2019
a, Tim x eN sao cho A+2=2^x+100
b, A+2 co phai la mot so chinh phuong khong
c, A =3+3^2+....+3^300
chung to A chia 13
d, 2A + 3 co phai la so chinh phuong ko
cho A=30+31+32+33+....+330 chung minh rang tong A ko phai la so chinh phuong
