1+3+3^2+3^3+.....+3^100=
giup mik với
Những câu hỏi liên quan
[ 100/3 ] + [ 100/3^2 ] + [100/3^3 ] + [ 100/3^4 ]
GIUP MIK NHA
\(A=\frac{100}{3}+\frac{100}{3^2}+\frac{100}{3^3}+\frac{100}{3^4}\)
\(\Rightarrow3A=100+\frac{100}{3}+\frac{100}{3^2}+\frac{100}{3^3}\)
\(\Rightarrow3A-A=100+\left(\frac{100}{3}-\frac{100}{3}\right)+\left(\frac{100}{3^2}-\frac{100}{3^2}\right)+\left(\frac{100}{3^3}-\frac{100}{3^2}\right)-\frac{100}{3^4}\)
\(\Rightarrow2A=100-\frac{100}{3^4}=100.\left(1-\frac{1}{3^4}\right)=100.\frac{80}{81}\)
\(\Rightarrow A=\frac{100.80}{2.81}=\frac{4000}{81}\)
lam giup mik voi
tinh gia tri cua bieu thu
D=(2^9.3+2^9.5)-2^12
(1+2+3+.....+100).(1^2+2^2+3^2+.....+100^2).(65.111-13.15.37)
C=2^10-2
F= 1+3^1+3^2+3^3 +.....+3^100
mik dag can gap lam
\(D=\left(2^9.3+2^9.5\right)-2^{12}\)
\(D=2^9.\left(3+2\right)-2^{12}\)
\(D=2^9.5-2^{12}\)
\(D=512.5-4096\)
\(D=2560-4096\)
\(D=-1536\)
\(\left(1+2+3+...+100\right).\left(1^2+2^2+3^2+...+100^2\right).\left(65.111-13.15.37\right)\)
\(=\left(1+2+3+...+100\right).\left(1^2+2^2+3^2+...+100^2\right).\left(7215-7215\right)\)
\(=\left(1+2+3+...+100\right).\left(1^2+2^2+3^2+...+100^2\right).0\)
\(=0\)
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D=(29.3+29.5)-212
D=((29.(3+5))-212
D=(29.8)-212
D=(29.23)-212
D=29+3-212
D=212-212
D=0
(1+2+3+...+100).(12+22+32+....+1002).(65.111-13.15.37)
=(1+2+3+...+100).(12+22+32+....+1002).7215-7215
=(1+2+3+...+100).(12+22+32+....+1002).0
=0
C=210-2
C=29+1-2
C=29.2-2
C=2.(29-1)
C=2.(512-1)\
C=2.511
C=1022
F=1+31+32+33+......+3100
F=3+31+32+33+......+3100
3F=3.(3+31+32+33+......+3100)
3F=32+32+33+34+......+3100
3F-F=3100+32-3-3
2F=3100+9-3-3
F=\(\frac{3^{100}+3}{2}\)
Chúc bn học tốt
3/3 .8/9.15/16....899/900
(-1).(-1)2.(-1)3.(-1)4...(-1)100
giup mik 2cau tinh nhanh vs mik tik cho nha ai cung tik
F=2+2^2+2^3+...+2^100
E=3^0+3^1+3^2+...+3^100
giúp mik với nhé mik cảm ơn!!!!!<3
\(F=2+2^2+2^3+...+2^{100}\)
\(2F=2^2+2^3+2^4+...+2^{101}\)
\(2F-F=\left(2^2+2^3+...+2^{101}\right)-\left(2+2^2+2^3+...+2^{100}\right)\)
\(F=2^{101}-2\)
Vậy...
\(E=3^0+3^1+3^2+...+3^{100}\)
\(E=1+3+3^2+...+3^{100}\)
\(3E=3+3^2+...+3^{101}\)
\(3E-3E=\left(3+3^2+...+3^{101}\right)-\left(1+3+3^2+...+3^{100}\right)\)
\(2E=3^{101}-1\)
\(E=\frac{3^{101}-1}{2}\)
Vậy...
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mấy bạn tinh giup mik bai nay voi
100-99+98-97.....+4-3+2-1
100 - 99 + 98 - 97 ...... + 4 - 3 +2 - 1
= ( 100 - 99) + ( 98 - 97) + ( 96 - 95) +.....( 4 - 3) + ( 2 - 1)
= 1 + 1 + ....+1 + 1 ( 50 số 1 ) = 50
tick đúng cho mình nha ^_^
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= (100 - 99 ) + ( 98 - + 97 ) + . . . + ( 4 - 3 ) + ( 2 - 1 )
= 1 + 1 + . . . + 1 + 1
50 số hạng
= 1 x 50 = 50
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100 + 98 + 96 + ....... + 2 - 97 - 95 - ...... - 3 - 1
= ( 100 + 98 + ...... + 2 ) - ( 97 + 95 + .......+ 3 + 1 )
= [ ( 2 + 100 ) x 50 : 2 ] - [ ( 1 + 97 ) x 49 : 2 ]
= 2550 - 2401
= 149
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a)A=1-2+3-4+...+99-100
b)B=1-2-3+4+5-6-7+...+97-98-99+100
c)C=2100-299s-998-...-22-2-1
giup mik vs a
A=-1++(-1)+..+-(1) có 50 số -1
=>A=-1x50=-50
B=(1-2-3+4)+(5-6-7+8)+...+(97-98-99+100)
B=0+0+0+..+0
B=0
C=2^100-(2^99+2^98+...+1)
C=2^100-(2^100-1)
C=1
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Chung minh rang:1/3-2/32+3/33-4/34+...+99/399-100/3100< 3/16 giup mik vs nhe! thanks ai giai dum mik tik cho2 tik lun
A=1+1/2+2/3+3/4+......+99/100 so sánh với B=100-(1/2+1/3+1/4+......+1/100)
giúp mik với
ta có
\(B=1+\left(1-\frac{1}{2}\right)+..+\left(1-\frac{1}{100}\right)\)
\(=1+\frac{1}{2}+\frac{2}{3}+..+\frac{99}{100}=A\)
Vậy A=B
Tìm x biết (1^3+2^3+3^3+...+100^3=(x-1)^2
giúp mik với đang gấp lắm (22:47 rồi) mik muốn ngủ lắm r nhưng phải nộp mong mn giúp mik với ❤️❤️❤️