A=[1+(-2)+(3)+4]+[5+(-6)+(-7)]+.....+[1997+(-1998)+(-1999)+2000] A=0+0+0+...+0=0
A=[1+(-2)+(3)+4]+[5+(-6)+(-7)]+.....+[1997+(-1998)+(-1999)+2000] A=0+0+0+...+0=0
Tính các tổng sau
\(a,S=1+\left(-2\right)+3+\left(-4\right)+...+\left(-2014\right)+2015\)
\(b,S=\left(-2\right)+4+\left(-6\right)+8+...+\left(-2014\right)+2016\)
\(c,S=1+\left(-3\right)+5+\left(-7\right)+...+2013+\left(-2015\right)\)
\(d,S=\left(-2015\right)+\left(-2014\right)+\left(-2013\right)+...+2015+2016\)
Tối giản phân số sau bằng cách thuận tiện:
\(\frac{\left(2^4+2^2+1\right)\left(4^4+4^2+1\right)\left(6^4+6^2+1\right)\left(8^4+8^2+1\right)\left(10^4+10^2+1\right)}{\left(3^4+3^2+1\right)\left(5^4+5^2+1\right)\left(7^4+7^2+1\right)\left(9^4+9^2+1\right)\left(11^4+11^2+1\right)}\)
Tính:
\(\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right)...\left(1-\frac{1}{1999}\right).\left(1-\frac{1}{2000}\right)\)
\(a.2\left(x-5\right)-3\left(x+7\right)=14\)
\(b.5\left(x-6\right)-2\left(x+3\right)=12\)
\(c.3\left(x-4\right)-\left(8-x\right)=12\)
\(d.-7\left(3x-5\right)+2\left(7x-14\right)=28\)
\(e.5\left(3-2x\right)+5\left(x-4\right)=6-4x\)
\(f.-5\left(2-x\right)+4\left(x-3\right)=10x-15\)
\(g.2\left(4x-8\right)-7\left(3+x\right)=|-4|\left(3-2\right)\)
\(h.8\left(x-|-7|\right)-6\left(x-2\right)=|-8|.6-50\)
cứ từ từ mà giải cũng đc
Thực hiện phép tính:
1, \(\left(\dfrac{-1}{2}\right)^2.\left|+8\right|-\left(-\dfrac{1}{2}\right)^3:\left|-\dfrac{1}{16}\right|\)
2, \(\left|-0,25\right|-\left(-\dfrac{3}{2}\right)^2:\dfrac{1}{4}+\dfrac{3}{4}.2017^0\)
3, \(\left|\dfrac{2}{3}-\dfrac{5}{6}\right|.\left(3,6:2\dfrac{2}{5}\right)^3\)
4, \(\left|\left(-0,5\right)^2+\dfrac{7}{2}\right|.10-\left(\dfrac{29}{30}-\dfrac{7}{15}\right):\left(-\dfrac{2017}{2018}\right)^0\)
5, \(\dfrac{8}{3}+\left(3-\dfrac{1}{2}\right)^2-\left|\dfrac{-7}{3}\right|\)
\(\left(5^{1998}+5^{2000}+5^{2002}\right):\left(5^{1999}+5^{1997}+5^{1995}\right)\)) bằng bao nhiêu ( trình bày luôn nha ) mình sẽ tik 5 tik cho các bạn
1.Tính C=\(\frac{\left(1+\frac{1999}{1}\right)\left(1+\frac{1999}{2}\right)\left(1+\frac{1999}{3}\right)...\left(1+\frac{1999}{1000}\right)}{\left(1+\frac{1000}{1}\right)\left(1+\frac{1000}{2}\right)\left(1+\frac{1000}{3}\right)...\left(1+\frac{1000}{1999}\right)}\)
1.tính
a)\(\left(4-\dfrac{12}{5}\right).\dfrac{25}{8}-\dfrac{2}{5}:\dfrac{-4}{25}\)
b)\(\left(\dfrac{-5}{24}+\dfrac{3}{4}-\dfrac{7}{12}\right):\left(\dfrac{-5}{16}\right)\)
c)\(\dfrac{6}{7}+\dfrac{5}{4}:\left(-5\right)-\dfrac{-1}{28}.\left(-2\right)^2\)
ai giải đc mik sẽ tick
1)\(4\left(x-5\right)-3\left(x+7\right)=-19\)
2)\(7\left(x-3\right)-5\left(3-x\right)=11x-5\)
3)\(4\left(2-x\right)+4\left(x-3\right)=14\)
4)\(-5\left(2-x\right)+4\left(x-3\right)=10x-15\)
5)\(7\left(x-9\right)-5\left(6-x\right)=-5+11x\)
6)\(-7\left(3x-5\right)+2\left(7x-14\right)=28\)
7)\(4\left(x-5\right)-3\left(x+7\right)=5.\left(-4\right)\)