\(\frac{1}{630}< \frac{1}{5^x}\le0,4\Leftrightarrow\frac{1}{630}< \frac{1}{5^x}< \frac{1}{2,5}\Leftrightarrow2,5< 5^x< 630\Leftrightarrow x\in\left\{4;3;2\right\}\)
KL: ............
bài 2 tìm x thuộc Z
a) \(\frac{-1}{5}< \frac{1}{x}< \frac{1}{7}\) b) \(\frac{14}{5}< \frac{x}{5}< 4\)
c)\(\frac{1}{3}< \frac{9}{x}< \frac{1}{2}\)
1) Giá trị \(x\in Z\) để \(\frac{x-5}{7-x}\) là số hữu tỉ dương. x = ?
2) Cặp số nguyên dương chẵn x; y thỏa mãn biểu thức \(\frac{x}{2}+\frac{3}{7}=\frac{5}{4}\). Vậy x = .... ; y = ....
3) Giá trị \(A=\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{11}}{\frac{3}{5}+\frac{3}{7}-\frac{3}{11}}+\frac{\frac{1}{4}-\frac{1}{5}+\frac{1}{7}}{\frac{3}{4}-\frac{3}{5}+\frac{3}{4}}\)
Bài 1: Thu gọn
a) \(\frac{1}{5}x^4y^3-3x^4y^3\)
b) \(5x^2y^5-\frac{1}{4}x^2y^5\)
c) \(\frac{1}{7}x^2y^3.\left(-\frac{14}{3}xy^2\right)-\frac{1}{2}xy.\left(x^2y^{\text{4}}\right)\)
d) \(\left(3xy\right)^2.\left(-\frac{1}{2}x^3y^2\right)\)
e) \(-\frac{1}{4}xy^2+\frac{2}{5}x^2y+\frac{1}{2}xy^2-x^2y\)
f) \(\frac{1}{2}x^4y.\left(-\frac{2}{3}x^3y^2\right)-\frac{1}{3}x^7y^3\)
g) \(\frac{1}{2}x^2y.\left(-10x^3yz^2\right).\frac{1}{4}x^5y^3z\)
h) \(4.\left(-\frac{1}{2}x\right)^2-\frac{3}{2}x.\left(-x\right)+\frac{1}{3}x^2\)
i) \(1\frac{2}{3}x^3y.\left(\frac{-1}{2}xy^2\right)^2-\frac{5}{4}.\frac{8}{15}x^3y.\left(-\frac{1}{2}xy^2\right)^2\)
k) \(-\frac{3}{2}xy^2.\left(\frac{3}{4}x^2y\right)^2-\frac{3}{5}xy.\left(-\frac{1}{3}x^4y^3\right)+\left(-x^2y\right)^2.\left(xy\right)^2\)
n) \(-2\frac{1}{5}xy.\left(-5x\right)^2+\frac{3}{4}y.\frac{2}{3}\left(-x^3\right)-\frac{1}{9}.\left(-x\right)^3.\frac{1}{3}y\)
m) \(\left(-\frac{1}{3}xy^2\right)^2.\left(3x^2y\right)^3.\left(-\frac{5}{2}xy^2z^3\right)^{^2}\)
p) \(-2y.\left|2\right|x^4y^5.\left|-\frac{3}{4}\right|x^3y^2z\)
1.tìm x
a.\(\frac{-5}{8}+x=\frac{4}{9}\)
b.\(1^3_4.x+1^1_2=-\frac{4}{5}\)
c.\(\frac{1}{4}+\frac{3}{4}x=\frac{3}{4}\)
d.\(x.\left(\frac{1}{4}+\frac{1}{5}\right)-\left(\frac{1}{7}+\frac{1}{8}\right)=0\)
e.\(\frac{3}{35}-\left(\frac{3}{5}+x\right)=\frac{2}{7}\)
f.\(\frac{3}{7}+\frac{1}{7}:x=\frac{3}{14}\)
g.\(\left(5x-1\right)\left(2x-\frac{1}{3}\right)=0\)
1 tìm x biết
a, \(x-4\sqrt{x}=0\)
b, \(|\frac{3}{5}\sqrt{x}-\frac{1}{20}|-\frac{3}{4}=\frac{1}{5}\)
c, \(|\frac{13}{5}\sqrt{x}-\frac{1}{30}|-\frac{2}{3}=\frac{1}{6}\)
a)\(\frac{x+1}{5}+\frac{x+1}{6}+\frac{x+1}{7}=\frac{x+1}{8}+\frac{x+1}{9}\)
b)\(\frac{x+6}{2015}+\frac{x+5}{2016}+\frac{x+4}{2017}=\frac{x+3}{2018}+\frac{x+2}{2019}+\frac{x+1}{2010}\)
c)\(\frac{x+6}{2016}+\frac{x+7}{2017}+\frac{x+8}{2018}=\frac{x+9}{2019}+\frac{x+10}{2020}+1\)
d)\(\frac{x-90}{10}+\frac{x-76}{12}+\frac{x-58}{14}+\frac{x-36}{16}+\frac{x-15}{17}=15\)
ai xong nhanh nhất và đúng em xin gửi 2 SP ạ
1.tìm x
a.\(\left(3^1_4:x\right).\left(-1^1_4\right)=\frac{-5}{3}-\frac{5}{6}\)
b.\(\frac{-1}{4}-\frac{3}{4}:x=\frac{-11}{36}\)
c.\(\left(-1^1_5+x\right):\left(-3^3_5\right)=\frac{-7}{4}+\frac{1}{4}:\frac{1}{8}\)
d.\(\frac{-22}{15}x+\frac{1}{3}=\left|-\frac{2}{3}+\frac{1}{5}\right|\)
\(\frac{3}{2}x\)---\(\frac{2}{5}\)= \(\frac{1}{3}\)x\(\frac{1}{3}x\) --- \(\frac{1}{4}\)
2/ 2x --\(\frac{1}{4}\)= \(\frac{5}{6}\)--- \(\frac{1}{2}x\)
3/ \(-\frac{5}{6}\)+ 3x = \(\frac{2}{3}\)--- \(\frac{1}{2}x\)
4/ \(\frac{5}{3}\)[ 3x --- 3 ] + \(\frac{1}{2}\)= \(\frac{1}{2}\)[ 2x ---- 1 ]
Tìm x : \(\left|\frac{3}{4}+\frac{1}{4}:x\right|=\frac{2}{5}\)
b) \(\frac{2}{3}x-1\frac{2}{5}=\frac{1}{2}x+0,8\)
c) \(\left|2x-1\right|-x=1\)
