Ta có
(1-1/(1+2))=(0/(1+2))=0
(1-1/(1+2+3))=(0/(1+2+3))=0
..........................................
.(1-1/(1+2+3+...+2006))=.(0/(1+2+3+...+2006))=0
=>0.0.0.0.....0=0
cho bieu thuc:
A=(6-2/3+1/2)-(5+5/3-3/2)-(3-7/3+5/2)
hay tinh gia tri cua A theo hai cach
cach 1:truoc het tinh gia tri tung bieu thuc trong ngoac
cach 2:bo dau ngoac roi nhom cac so hang thich hop
Cho bieu thuc A = \(^{x2+4x+3}\)
a Tinh gia tri bieu thuc tai x= \(\frac{-1}{2}\)
b Tinh gia tri x de bieu thuc A bang 0
tinh gia tri bieu thuc a = \(\sqrt{4+\sqrt[3]{8+\frac{2}{3}+3^{10}}\frac{1}{1\times2}+\frac{1}{2\times3}+...+\frac{1}{99\times100}}\)
tinh gia tri bieu thuc a = \(\sqrt{4+\sqrt[3]{8}+\frac{2}{3}+3^{10}}\frac{1}{1\times2}+\frac{1}{2\times3}+...+\frac{1}{99\times100}\)
tinh gia tri bieu thuc a = \(\sqrt{4+\sqrt[3]{8+\frac{2}{3}+3^{10}}\frac{1}{1\times2}+\frac{1}{2\times3}+...+\frac{1}{99\times100}}\)
tinh gia tri bieu thuc A=2^2015-(2^2014+2^2013+...+2+1)
tinh gia tri cua bieu thuc: B=1*2*3+2*3*4+3*4*5+4*5*6+.....+17*18*19
Tinh gia tri cua bieu thuc
M=5xy-10=3y tai x=2 ; y=-3
N =2(x^2-1) +3x-2 tai x=-1
tinh gia tri bieu thuc tai |x|=1/3
A =x3- 5x2 + 10x -2
gip mk voi
