\(i=\frac{30}{IxI+2}\le\frac{30}{2}=15\) Max i = 15 khi x =0 ( vì /x/ >/ 0 với mọi x )
\(m=\frac{48}{IxI+Iy-5I+12}\le\frac{48}{12}=4\) Max m = 4 khi x =0 ; y =5 ( vì /x/ >/ 0 ; / y -5 / >/ 0 với mọ x ; y )
Tìm x biết : \(\frac{\left|x-2\right|}{12}+\frac{\left|x-2\right|}{20}+\frac{\left|x-2\right|}{30}+\frac{\left|x-2\right|}{42}=\frac{70^5}{2^3\cdot21^6}\)
Tìm x, biết:
\(\frac{3}{\left(x+2\right)\left(x+5\right)}+\frac{5}{\left(x+5\right)\left(x+10\right)}+\frac{7}{\left(x+10\right)\left(x+17\right)}=\frac{x}{\left(x+2\right)\left(x+17\right)}\left(x\notin-2;-5;-10;-17\right)\)
\(\frac{2}{\left(x-1\right)\left(x-3\right)}+\frac{5}{\left(x-3\right)\left(x-8\right)}+\frac{12}{\left(x-8\right)\left(x-20\right)}-\frac{1}{x-20}=-\frac{3}{4}\)
Với \(x\notin1;3;8;20\)
\(\frac{x+1}{10}+\frac{2+1}{11}\frac{x+1}{12}=\frac{x+1}{13}+\frac{x+1}{14}\)
\(\frac{x-10}{30}+\frac{x-14}{43}+\frac{x-5}{95}+\frac{x-148}{8}=0\)
Tìm x biết :
\(\left(\frac{x-2}{12}\right)+\left(\frac{x-2}{20}\right)+\left(\frac{x-2}{30}\right)+\left(\frac{x-2}{42}\right)+\left(\frac{x-2}{56}\right)+\left(\frac{x-2}{72}\right)=\frac{16}{9}\)
giúp mk nha
Bài 2 :
a, \(\frac{3}{\left(x+2\right)\left(x+5\right)}+\frac{5}{\left(x+5\right)\left(x+10\right)}+\frac{7}{\left(x+10\right)\left(x+17\right)}=\frac{x}{\left(x+2\right)\left(x+17\right)}\)
b, \(\frac{2}{\left(x-1\right)\left(x-3\right)}+\frac{5}{\left(x-3\right)\left(x-8\right)}+\frac{12}{\left(x-8\right)\left(x-20\right)}-\frac{1}{\left(x-20\right)}=\frac{-3}{4}\)
Tìm x:
\(\frac{\left(13\frac{2}{9}-15\frac{2}{3}\right)\cdot\left(30^2-5^4\right)}{\left(18\frac{3}{7}-17\frac{1}{4}\right)\cdot\left(25-12\cdot5^2\right)}\cdot x=\frac{\frac{2}{11}+\frac{3}{13}+\frac{4}{15}+\frac{5}{17}}{4\frac{1}{11}+\frac{5}{13}+\frac{9}{15}+\frac{13}{17}}\)
Tìm GTNN
a.\(A=\left|\frac{x}{5}+\frac{23}{2}\right|+\left|y-\frac{14}{3}\right|+2019\)
b. \(B=\left(x-\frac{5}{4}\right)^{20}+\left(y+\frac{4}{3}\right)^{30}-11\)
AI LÀM NHANH TỚ TIM
1/ Tính tổng:
M =\(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}\)
2/Tìm X:
\(\frac{1}{21}+\frac{1}{28} +\frac{1}{36} +.....+\frac{2}{x.\left(x+1\right)}=\frac{2}{9}\)
3/Tính tích sau rồi tìm số nghịch đảo của kết quả:
\(T=\left(1-\frac{1}{3}\right)\left(1-\frac{1}{5}\right)\left(1-\frac{1}{7}\right)\left(1-\frac{1}{9}\right)\left(1-\frac{1}{11}\right)\left(1-\frac{1}{2}\right)\left(1-\frac{1}{4}\right)\left(1-\frac{1}{6}\right)\left(1-\frac{1}{8}\right)\left(1-\frac{1}{10}\right)\)
4/ TÍnh giá trị của biểu thức:
\(\frac{1^2}{1.2}.\frac{2^2}{2.3}.\frac{3^2}{3.4}\frac{4^2}{4.5}\)
a) Tính
\(A=\left(1-\frac{1}{2}\right)\cdot\left(1-\frac{1}{3}\right)\cdot\left(1-\frac{1}{4}\right)\cdot\cdot\cdot\left(1-\frac{1}{2014}\right)\cdot\left(1-\frac{1}{2015}\right)\cdot\left(1-\frac{1}{2016}\right)\)
b) Tìm x:
\(\frac{x-2}{12}+\frac{x-2}{20}+\frac{x-2}{30}+\frac{x-2}{42}+\frac{x-2}{56}+\frac{x-2}{72}=\frac{16}{9}\)
A) \(\frac{3}{\left(X+2\right)\left(X+5\right)}\)+\(\frac{5}{\left(X+5\right)\left(X+7\right)}+\frac{7}{\left(X+10\right)\left(X+17\right)}=\frac{X}{\left(X+2\right)\left(X+17\right)}\)
B) \(\frac{2}{\left(X-1\right)\left(X-3\right)}+\frac{5}{\left(X-3\right)\left(x-8\right)}+\frac{12}{\left(X-8\right)\left(X-20\right)}-\frac{-1}{X-20}=\frac{3}{4}\)
