hộ mình với ak
Bài 1. Thực hiện phép tính
a) \(\frac{25}{12} + \frac{-4}{12}\)
b) \(\frac{-7}{15} - \frac{-2}{15}\)
c) \(\frac{3}{8} + \frac{-14}{6}\)
d) \(3 \frac{1}{4} - 1 \frac{1}{3}\)
e) \(\frac{2}{3} + \frac{-10}{6} + \frac{-4}{3}\)
f) \(\frac{7}{3} - \left( \frac{-1}{4} - \frac{5}{12} \right)\)
g) \(\frac{-4}{3} : \frac{13}{9}\)
h) \(\frac{-5}{7} \cdot \frac{49}{3} : \frac{-7}{6}\)
Bài 2. Tính hợp lí
a) \(\frac{3}{8} \cdot 1 - \frac{3}{8} \cdot \frac{1}{3}\)
b) \(\left( \frac{-5}{9} \right) \cdot \frac{3}{11} + \left( \frac{-8}{18} \right) \cdot \frac{3}{11}\)
Bài 3. Thực hiện phép tính:
a) \(A = \left\{ \left[ \left( \frac{1}{2} - \frac{2}{3} \right)^2 : 2 \right] - (-3)^0 \cdot \frac{2}{3} \right\}\)
b) \(B = \left[ \left( \frac{2}{5} + 1 \right) : \frac{2}{3} \right] \cdot \left( \frac{3}{4} - \frac{1}{8} \right)^2\)
Bài 3:
a: \(A=\left\lbrace\left\lbrack\left(\frac12-\frac23\right)^2:2\right\rbrack-\left(-3\right)^0\right\rbrace\cdot\frac23\)
\(=\left\lbrack\left(\frac36-\frac46\right)^2:2-1\right\rbrack\cdot\frac23\)
\(=\left\lbrack\left(-\frac16\right)^2:2-1\right\rbrack\cdot\frac23=\left(\frac{1}{36}\cdot\frac12-1\right)\cdot\frac23=\left(\frac{1}{72}-1\right)\cdot\frac23\)
\(=-\frac{71}{72}\cdot\frac23=-\frac{71}{36\cdot3}=-\frac{71}{108}\)
b: \(B=\left\lbrack\left(\frac25+1\right):\frac23\right\rbrack\cdot\left(\frac34-\frac18\right)^2\)
\(=\left\lbrack\frac75\cdot\frac32\right\rbrack\cdot\left(\frac68-\frac18\right)^2\)
\(=\frac{21}{10}\cdot\left(\frac58\right)^2=\frac{21}{10}\cdot\frac{25}{64}=\frac{21}{2}\cdot\frac{5}{64}=\frac{105}{128}\)
Bài 2:
a: \(\frac38\cdot1\frac13-\frac38\cdot3\frac13\)
\(=\frac38\left(1+\frac13-3-\frac13\right)\)
\(=-2\cdot\frac38=-\frac34\)
b: \(\left(-\frac59\right)\cdot\frac{3}{11}+\left(-\frac{8}{18}\right)\cdot\frac{3}{11}\)
\(=\frac{3}{11}\left(-\frac59-\frac49\right)\)
\(=\frac{3}{11}\cdot\frac{-9}{9}=-\frac{3}{11}\)
Bài 1:
a: \(\frac{25}{12}+\frac{-4}{12}=\frac{25-4}{12}=\frac{21}{12}=\frac74\)
b: \(\frac{-7}{15}-\frac{-2}{15}=-\frac{7}{15}+\frac{2}{15}=-\frac{5}{15}=-\frac13\)
c: \(\frac38+\frac{-14}{6}=\frac{9}{24}-\frac{56}{24}=\frac{9-56}{24}=\frac{-47}{24}\)
d: \(3\frac14-1\frac13=\frac{13}{4}-\frac43\)
\(=\frac{39}{12}-\frac{16}{12}=\frac{39-16}{12}=\frac{23}{12}\)
e: \(\frac23+\frac{-10}{6}+\frac{-4}{3}=\frac23-\frac53-\frac43=\frac{-7}{3}\)
f: \(\frac73-\left(-\frac14-\frac{5}{12}\right)=\frac73+\frac14+\frac{5}{12}\)
\(=\frac{28}{12}+\frac{3}{12}+\frac{5}{12}=\frac{28+3+5}{12}=\frac{36}{12}=3\)
g: \(-\frac43:\frac{13}{9}=-\frac43\cdot\frac{9}{13}=\frac{-4}{13}\cdot3=-\frac{12}{13}\)
h: \(-\frac57\cdot\frac{49}{3}:\frac{-7}{6}=\frac57\cdot\frac{49}{3}\cdot\frac67=\frac53\cdot6=10\)
