Bài 1:
a: \(\frac45+\left(-\frac{15}{18}-\frac45\right)\)
\(=\frac45-\frac{15}{18}-\frac45=-\frac{15}{18}=-\frac56\)
b: \(-\frac{9}{14}:\frac{3}{17}+\frac{-5}{14}:\frac{3}{17}\)
\(=\left(-\frac{9}{14}-\frac{5}{14}\right):\frac{3}{17}\)
\(=-1\cdot\frac{17}{3}=-\frac{17}{3}\)
c: \(\left(-\frac12\right)^2\cdot\left(-16\right)+\left|-4\right|-\sqrt{49}\cdot\left(-\frac17\right)^2\)
\(=\frac14\cdot\left(-16\right)+4-7\cdot\frac{1}{49}\)
\(=-4+4-\frac17=-\frac17\)
d: \(\frac47-\left(\frac{3}{27}-\frac47\right)\)
\(=\frac47-\frac{3}{27}+\frac47\)
\(=\frac87-\frac19=\frac{72-7}{63}=\frac{65}{63}\)
e: \(25\frac{13}{19}:\left(-\frac54\right)-45\frac{13}{19}:\left(-\frac54\right)\)
\(=\left(25+\frac{13}{19}-45-\frac{13}{19}\right):\left(-\frac54\right)\)
\(=-20\cdot\frac{-4}{5}=16\)
f: \(5:\left(-\frac52\right)^2+\frac{2}{45}\cdot\sqrt{\frac{81}{4}}-\left(-2021\right)^0+0,75\)
\(=5:\frac{25}{4}+\frac{2}{45}\cdot\frac92-1+0,75\)
\(=\frac{20}{25}+\frac{9}{45}-0,25=\frac45+\frac15-0,25=1-0,25=0,75\)
Bài 2:
a: \(\left(\frac{5}{18}-x\right)-\frac{11}{15}=-\frac25\)
=>\(\frac{5}{18}-x=-\frac25+\frac{11}{15}=\frac{11}{15}-\frac{6}{15}=\frac{5}{15}=\frac13\)
=>\(x=\frac{5}{18}-\frac13=-\frac{1}{18}\)
b: \(-\frac58+\left|7-x\right|=\sqrt{\frac{81}{64}}\)
=>\(\left|x-7\right|-\frac58=\frac98\)
=>\(\left|x-7\right|=\frac98+\frac58=\frac{14}{8}=\frac74\)
=>\(\left[\begin{array}{l}x-7=\frac74\\ x-7=-\frac74\end{array}\right.\Rightarrow\left[\begin{array}{l}x=\frac74+7=\frac{35}{4}\\ x=-\frac74+7=-\frac74+\frac{28}{4}=\frac{21}{4}\end{array}\right.\)
c: \(\frac{2^{4x+1}}{2}=16\)
=>\(2^{4x+1}=2\cdot16=32=2^5\)
=>4x+1=5
=>4x=4
=>x=1
d: \(\frac{48}{35}-\frac{13}{35}:x=-\frac{22}{35}\)
=>\(\frac{13}{35}:x=\frac{48}{35}+\frac{22}{35}=\frac{70}{35}=2\)
=>\(x=\frac{13}{35}:2=\frac{13}{70}\)
e: \(\left|1\frac12-x\right|-\frac34=\frac54\)
=>\(\left|\frac32-x\right|=\frac34+\frac54=2\)
=>\(\left[\begin{array}{l}\frac32-x=2\\ \frac32-x=-2\end{array}\right.\Rightarrow\left[\begin{array}{l}x=\frac32-2=\frac{-1}{2}\\ x=\frac32+2=\frac72\end{array}\right.\)
f: \(\left(3x-\frac12\right)^2+\frac{21}{25}=1\)
=>\(\left(3x-\frac12\right)^2=1-\frac{21}{25}=\frac{4}{25}\)
=>\(\left[\begin{array}{l}3x-\frac12=\frac25\\ 3x-\frac12=-\frac25\end{array}\right.\Rightarrow\left[\begin{array}{l}3x=\frac25+\frac12=\frac{9}{10}\\ 3x=-\frac25+\frac12=\frac{-4+5}{10}=\frac{1}{10}\end{array}\right.\Rightarrow\left[\begin{array}{l}x=\frac{3}{10}\\ x=\frac{1}{30}\end{array}\right.\)
