S=3+3mũ2+3mũ3+....+3mũ2022
S=3+3mũ2+3mũ3+....+3mũ2022
S=3+3^2+3^3+...+3^2022
3S=3.(3+3^2+3^3+...+3^2022)
3S=3^2+3^3+3^4+...+3^2023
⇒3S-S=(3^2+3^3+3^4+...+3^2023)-(3+3^2+3^3+...+3^2022)
⇒2S=3^2023-3
⇒S=3^2023-3 / 2
S=3+3^2+3^3+...+3^2022
=>3S=3^2+3^3+3^4+...+3^2023
=>3S-S=(3^2+3^3+3^4+...+3^2023)-(3+3^2+3^3+...+3^2022)
=>2S=3^2023-3
=>S=\(\dfrac{3^{2023}-3}{2}\)
Vậy S=\(\dfrac{3^{2023}-3}{2}\)
Chứng minh rằng:
S=3+3mũ2+3mũ3+3mũ4+...+3mũ100 chia hết cho 4
cho S =1 +3+3mũ2 +3mũ3+ .......................................................................................................................+ 3 mũ 119
a, tính S
b, cmr S chia hết cho 13
c,cmr S chia hết cho 40
a/
\(3S=3+3^2+3^3+3^4+...+3^{120}\)
\(2S=3S-S=3^{120}-1\Rightarrow S=\frac{3^{120}-1}{2}\)
b/ \(S=\left(1+3+3^2\right)+\left(3^3+3^4+3^5\right)+...+\left(3^{117}+3^{118}+3^{119}\right)\)
\(S=13+3^3\left(1+3+3^2\right)+...+3^{117}\left(1+3+3^2\right)\)
\(S=13+3^3.13+...+3^{117}.13=13\left(1+3^3+...+3^{117}\right)\) chia hết cho 13
c/
\(S=\left(1+3+3^2+3^3\right)+\left(3^4+3^5+3^6+3^7\right)+...+\left(3^{116}+3^{117}+3^{118}+3^{119}\right)\)
\(S=\left(1+3+3^2+3^3\right)+3^4\left(1+3+3^2+3^3\right)+...+3^{116}\left(1+3+3^2+3^3\right)\)
\(S=40+3^4.40+...+3^{116}.40=40\left(1+3^4+...+3^{116}\right)\) chia hết cho 40
3 mũ 1+3mũ2+3mũ3+3mũ4+...3mũ199
\(A=3^1+3^2+3^3+3^4+...+3^{199}\)
\(3A=3^2+3^3+3^4+3^5+...+3^{200}\)
\(3A-A=\left(3^2+3^3+3^4+...+3^{200}\right)-\left(3^1+3^2+3^3+...+3^{199}\right)\)
\(2A=3^{200}-3^1\)
\(A=\frac{3^{200}-3}{2}\)
=))
Đặt \(A=3^1+3^2+3^3+...+3^{199}\)
\(\Rightarrow3A=3^2+3^3+3^4+...+3^{200}\)
Lấy 3A trừ A theo vế ta có :
\(3A-A=\left(3^2+3^3+3^4+..+3^{200}\right)-\left(3^1+3^2+3^3+..+3^{199}\right)\)
\(2A=3^{200}-1\)
\(A=\frac{3^{200}-1}{2}\)
Vậy \(3^1+3^2+3^3+..+3^{199}=\frac{3^{200}-1}{2}\)
xích ma 3x chạy từ 1 tới 199 kết quả là \(^{\text{1,328069944 nhân}10^{95}}\)
3mũ6 chia 3mũ2 cộng 2mũ3 nhân 2mũ2 trừ 3mũ3 nhân 3
\(3^6:3^2+2^3.2^2-3^3.3\)
\(=3^4+2^5-3^4\)
\(=3^4-3^4+2^5\)
\(=0+2^5=2^5\)
\(3^6:3^2+2^3.2^2-3^3.3\\ =3^4+2-3^4\\ =\left(3^4-3^4\right)+2\\ =0+2\\ =2.\)
Sửa hộ mk thành \(2^5\) bắt đầu từ dòng thứ 2 nhé.
tính tổng G= 1-3+3mũ2-3mũ3+3mũ4-...-3mũ99+3mũ100
G=1-3+32-33+34-...-399+3100
3G=3-32+33-34+35-....-3100+3101
3G+G=(3-32+33-34+35-....-3100+3101)+(1-3+32-33+34-...-399+3100)
4G = 3101+1
G=\(\frac{3^{101}+1}{4}\)
cho C=3- 3mũ2+ 3mũ3- 3mũ4+....+ 3mũ23- 3mũ24. CM Cchia hết cho 420
tính tích của:
a,3mũ1*3mũ2*3mũ3*......*3mũ100
b,1mũ1*2mũ2*3mũ3*4mũ4*...*100mũ100
a)31x32x33x........x3100
=31+2+3+4+...+100
=3(100+1)x(100-1+1):2
=3101x100:2
=35050
Bài b mình không biết làm
\(A=\)\(-\frac{1}{3}+\frac{1}{3^2}-\frac{1}{3^3}+\frac{1}{3^4}-...+\frac{1}{3^{50}}-\frac{1}{3^{51}}\)
\(3A=-1+\frac{1}{3}-\frac{1}{3^2}+...+\frac{1}{3^{49}}-\frac{1}{3^{50}}\)
\(4A=-1-\frac{1}{3^{51}}\)
\(A=\frac{-1-\frac{1}{3^{51}}}{4}\)
k cho mik nha