a) Tìm tập hợp các số nguyên x, biết rằng\(4\dfrac{5}{9}:2\dfrac{5}{18}-7< x< \left(3\dfrac{1}{5}:3,2+4,5.1\dfrac{31}{45}\right):\left(-21\dfrac{1}{2}\right)\)
b) tìm x, biết \(\left|x+\dfrac{1}{2}\right|+\left|x+\dfrac{1}{6}\right|+\left|x+\dfrac{1}{12}\right|+\left|x+\dfrac{1}{20}\right|+....+\left|x+\dfrac{1}{110}\right|-11x\)
c)Tính gt biểu thức \(C=2x^3-5y^3+2015\) tại x,y thỏa mãn \(\left|x-1\right|+\left(y+2\right)^{20}=0\)
Tìm x, sao cho:
a) \(1-2x< 7\) b) \(\left(x-1\right)\left(x-2\right)>0\) c)\(\left(x-2\right)^2\left(x+1\right)\left(x-4\right)< 0\) d)\(\dfrac{x^2\left(x-3\right)}{x-9}< 0\)
Tìm X sao cho:
a, \(1-2x< 7\)
b, \(\left(x-1\right)\left(x-2\right)>0\)
c, \(\left(x-2\right)^2\left(x+1\right)\left(x-4\right)< 0\)
d, \(\dfrac{x^2\left(x-3\right)}{x-9}< 0\)
thực hiên phép tính :
a, \(\left(3^2\right)^2-\left(2^3\right)^2-\left(-5^2\right)^2\)
b, \(2^3+3.\left(-\dfrac{1}{2}\right)^0-\left(\dfrac{1}{2}\right)^2.4+\left(\left(-2\right)^2:\dfrac{1}{2}\right):8\)
c, \(\left(4.2^5\right):\left(2^3.\dfrac{1}{16}\right)\)
d, \(A=\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\dfrac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
a) Cho \(M=\dfrac{42-x}{x-15}\) . Tìm số nguyên x để m đạt giá trị nhỏ nhất .
b) Tìm x sao cho \(\left(\dfrac{1}{2}\right)^x+\left(\dfrac{1}{2}\right)^{x-4}=17\)
Cho \(A=\dfrac{\left|2x-3\right|+\left|6y-7\right|}{\left|9-6x\right|+\left|18y-21\right|}-\dfrac{\left(x-2\right)^2+\left(2y-4\right)^2}{\left(3x-6\right)^2+\left(12-6y\right)^2}\). Rút gọn A
1,Tìm a\(\in\Sigma\),biết:
\(\left(a^2-1\right)\left(a^2-4\right)\left(a^2-7\right)\left(a^2-10\right)< 0\)
2,Tìm GTNN của các biểu thức:
a,A\(=\)\(x^4+3x^2+2\)
b,B\(=\left(x^4+5\right)^2\)
c,C\(=\left(x-1\right)^2+\left(y+2\right)^2-2\)
3,Tìm GTLN của các biểu thức:
a,A\(=5-3\left(2x-1\right)^2\)
b,B\(=\frac{1}{2\left(x-1\right)^2+3}\)
c,C\(=\frac{x^2+8}{x^2+2}\)
Tinh:
\(A=\dfrac{(13\dfrac{1}{4}-2\dfrac{5}{27}-10\dfrac{5}{6}).203\dfrac{1}{25}+46\dfrac{3}{4}}{(1\dfrac{3}{7}+\dfrac{10}{3}):\left(12\dfrac{1}{3}-14\dfrac{2}{7}\right)}\)
\(B=\dfrac{\left(81,624:4,8-4.505\right)^2+125.0,75}{\left\{\left[\left(0,44\right)^2:0,88+3,53\right]^2-\left(2,75\right)^2\right\}:0,52}\)
Bài 1. a, Cho A = \(\left(\dfrac{1}{2}-1\right)\left(\dfrac{1}{3}-1\right).....\left(\dfrac{1}{10}-1\right)\)
So sánh A với \(\dfrac{-1}{9}\)
Bài 2. Cho A = \(\left(\dfrac{1}{2}-1\right)\left(\dfrac{1}{3}-1\right)....\left(\dfrac{1}{2008}-1\right)\left(\dfrac{1}{2009}-1\right)\)
B = \(\left(-1\dfrac{1}{2}\right)\left(-1\dfrac{1}{3}\right)....\left(-1\dfrac{1}{2007}\right)\left(-1\dfrac{1}{2008}\right)\)
Tính A . B ?