tinh tong S= 3/2 +3/2^2 +3/2^3+......+3/2^9
Những câu hỏi liên quan
bai1:tinh tong S=1.3+3.5+5.7+...+99.101
bai2 :tinh tong S=1.4+4.7+7.10+...+2017.2020
bai 3: tinh tong N=2.4+4.6+6.8+..+100.102
bai 4: tinh tóng=2.6+6.10+10.14+14.18+...+42.46+50.54
bai 5:tinh tongB=2^2+4^2+6^2+...+100^2
bai 6:C=1^2+3^2+...+100^2
bai7: biet 1^2+2^2+3^2+...+10^2=385 tinh tong 2^2+4^2+6^2+...+20^2
bai 8: tinh tong s=1^2+2^2+3^2+...+99^2
Bài 1 :
\(S=1.3+3.5+5.7+...+99.101=3+15+35+...9999\)
Ta thấy :
\(3=2^2-1\)
\(15=4^2-1\)
\(35=6^2-1\)
.....
\(9999=100^2-1\)
\(\Rightarrow S=2^2+4^2+...+100^2-\left(1\right).\left(\left(100-2\right):2+1\right)\)
\(\Rightarrow S=\dfrac{100.\left(100+1\right)\left(2.100+1\right)}{6}-51\)
\(\Rightarrow S=\dfrac{100.101.201}{6}-51=338299\)
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nhanh len nhé mik đang cần gấp ai lam trước mik tích cho
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Bài 6 :
\(C=1^2+2^2+...+100^2=\dfrac{100.\left(100+1\right)\left(2.100+1\right)}{6}=\dfrac{100.101.201}{6}=338350\)
Bài 9 :
\(S=1^2+2^2+3^2+...+99^2=\dfrac{99.\left(99+1\right)\left(2.99+1\right)}{6}=\dfrac{99.100.199}{6}=328350\)
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Xem thêm câu trả lời
tim so tu nhien x,y sao cho:x /9 -3 / y = 1 / 18
cho A= 1/1^2 + 1/2^2+1/3^2 1/4^2+...+1/50^2. chung minhA<2
tinh tong S=3+3/2+3/2^2+...3/2^9
ban nao giup voi nhe to can on truoc
tinh tong S=2013+2013/1+2+2013/1+2+3+...+2013/1+2+3+...+2012
Tinh tong S = 1×2+2×3+3×4+4×5+•••••+99×100
S=1*2+2*3+3*4+...+99*100
3S=3*(1*2+2*3+3*4+...+99*100)
3S=1*2*3+2*3*3+3*4*3+...+99*100*3
3S=1*2*(3-0)+2*3*(4-1)+3*4*(5-2)+...+99*100*(101-98)
3S=1*2*3-1*2*0+2*3*4-2*3*1+3*4*5-3*4*2+...+99*100*101-99*100*98
3S=(1*2*3-2*3*1)+(2*3*4-3*4*2)+...+(98*99*100-99*100*98)+99*100*101
3S=0+0+...+0+999900
3S=999900
S=999900/3
S=333300
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3S = 1.2.3 + 2.3.3 + 3.4.3 +...+99.100.3
=1.2.3 + 2.3.(4-1)+3.4(5-2)+...+99.100(101-98)
=1.2.3+2.3.4-1.2.3+3.4.5-2.3.4+...+99.100.101-98.99.100
= 99.100.101
=999900
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Nga Nguyễn ơi, bạn chưa chia cho 3 rồi
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tinh tong s=1/2^2+1/3^2+...+ 1/10^2
Tinh tong S= 12+22+32+42+..............+202 - (1+2+3+...........+20)
S=
tinh tong S = 1"2 + 2"2 + 3"2 + ..... +100"2 (co cach giai )
tinh tong S=1+2^2+3^3=...+10^10 bang cach su dung cau len lap For...do
uses crt;
var i,j:integer;
s:real;
{----------chuong-trinh-con---------------}
function luythua(x,y:integer):real;
var lt:real;
i:integer;
begin
lt:=1;
for i:=1 to y do
lt:=lt*x;
luythua:=lt;
end;
{---------------chuong-trinh-chinh---------------------}
s:=0;
for i:=1 to 10 do
for j:=1 to 10 do
if i=j then s:=s+luythua(i,j);
writeln(s:0:0);
readln;
end.
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Tinh tong S=1/1×2+1/2×3+1/3×4+...+1/2014×2015+1/2015×2016
\(S=\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+....+\frac{1}{2015.2016}\)
\(S=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+....+\frac{1}{2015}-\frac{1}{2016}\)
\(S=1-\frac{1}{2016}=\frac{2015}{2016}\)
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\(S=\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-........+\frac{1}{2015}-\frac{1}{2016}\)
\(S=\frac{1}{1}-\left(-\frac{1}{2}+\frac{1}{2}\right)+\left(-\frac{1}{3}+\frac{1}{3}\right)+......+\left(-\frac{1}{2015}+\frac{1}{2015}\right)-\frac{1}{2016}\)
\(S=\frac{1}{1}-\frac{1}{2016}=\frac{2015}{2016}\)
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