tinh gia tri cua 1^2+2^2+3^2..+100^2'
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tinh gia tri cua 1^2+2^2+3^2..+100^2'
tinh gia tri cua 1^2+2^2+3^2..+100^2'
Cho x+y=2, tinh gia tri cua bieu thuc:
M=3(x^2+y^2)-(x^3+y^3)+1
Bai 2:Cho a+b=5,tinh gia tri bieu thuc:
M=3a^2-2a+3b^2-2b+6ab+100
A=99-(1/2 + 1/3+1/4+...+1/100) : (1/2+2/3+3/4+...+99/100)
tinh gia tri cua A.
cho x+y =1 . tinh gia tri cua bieu thuc A=x^3+y^3+3xy
chox-y=1. tinh gia tri cua bieu thuc B=x^3-y^3-3xy
cho x+y=1 . tinh gia tri cua bieu thuc C=x^3+y^3+3xy(x^2+y^2)+6x^2*y^2(x+y)
Câu 1: Ta có: A = \(x^3+y^3+3xy=x^3+y^3+3xy\times1=x^3+y^3+3xy\left(x+y\right)\)
\(=\left(x+y\right)^3=1^3=1\)
Câu 2: Ta có: \(B=x^3-y^3-3xy=\left(x-y\right)\left(x^2+xy+y^2\right)-3xy\)
\(=x^2+xy+y^2-3xy=x^2-2xy+y^2=\left(x-y\right)^2=1^2=1\)
Câu 3: Ta có: \(C=x^3+y^3+3xy\left(x^2+y^2\right)-6x^2.y^2\left(x+y\right)\)
\(=x^3+y^3+3xy\left(x^2+2xy+y^2-2xy\right)+6x^2y^2\)
\(=x^3+y^3+3xy\left(x+y\right)^2-3xy.2xy+6x^2y^2\)
\(=x^3+y^3+3xy.1-6x^2y^2+6x^2y^3\)
\(=x^3+y^3+3xy\left(x+y\right)=\left(x+y\right)^3=1^3=1\)
cho bieu thuc a=-1/3+1/3^2-1/3^3+1/3^4-1/3^5+...+1/3^100 tinh gia tri cua bieu thuc b=4/a/+1/3^100
A=1/2^1+2/2^2+2/2^3+...+2/2^100
Tinh gia tri cua A
hãy giúp mình nha !!!
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
\(D=\left(2^9.3+2^9.5\right)-2^{12}\)
\(D=2^9.\left(3+2\right)-2^{12}\)
\(D=2^9.5-2^{12}\)
\(D=512.5-4096\)
\(D=2560-4096\)
\(D=-1536\)
\(\left(1+2+3+...+100\right).\left(1^2+2^2+3^2+...+100^2\right).\left(65.111-13.15.37\right)\)
\(=\left(1+2+3+...+100\right).\left(1^2+2^2+3^2+...+100^2\right).\left(7215-7215\right)\)
\(=\left(1+2+3+...+100\right).\left(1^2+2^2+3^2+...+100^2\right).0\)
\(=0\)
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
Bai 1:Tinh tong T=1-2+2^2-2^3+....+2^1000
Bài 2:Tinh gia tri nho nhát A=|x+10|+2015
Bài 3:Tim gia tri lon nhát cua biểu thức: |-x+4|+2011
Giúp minh giai may bai nay voi
Bài 1 nhân cả 2 vế với 2 rồi trừ vế
Bài 2 ta có |x+10|>_0với mọi x
=>|x+10|+2015>_2015 hay A>_2015
Dấu bằng xảy ra <=>|x+10|=0
=>x+10=0
Bài 3ta có |-x+4|>_0 với mọi x
=>|-x+4|+2011>_2011
dấu bằng xảy ra <=>|-x+4|=0
=>-x+4=0
=>x=4
=>x=-10
Bài 2