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Bài 2:
b: x+25%x=-1,25
=>1,25x=-1,25
hay x=-1
c: x-75%x=1/4
=>1/4x=1/4
hay x=1
Bài 2:
a: =3/2-11/4=6/4-11/4=-5/4
b: =-49/6-17/2=-49/6-51/6=-100/6=-50/3
a
\(5\frac{4}{7}:x+=13\)
\(\frac{39}{7}:x=13\)
\(x=\frac{39}{7}:13\)
\(x=\frac{3}{7}\)
\(\frac{4}{7}x=\frac{9}{8}-0,125\)
\(\frac{4}{7}x=1\)
\(x=1:\frac{4}{7}\)
\(x=\frac{7}{4}=1\frac{3}{4}\)
Thực hiện phép tính
a ) \(\frac{2}{5}+\frac{-1}{6}-\frac{3}{4}-\frac{-2}{3}\)
= \(\frac{2}{5}+\frac{-1}{6}+\frac{-3}{4}+\frac{2}{3}\)
= \(\left(\frac{2}{5}+\frac{-3}{4}\right)+\left(\frac{-1}{6}+\frac{2}{3}\right)\)
= \(\left(\frac{8}{20}+\frac{-15}{20}\right)+\left(\frac{-1}{6}+\frac{4}{6}\right)\)
= \(\left(\frac{8+\left(-15\right)}{20}\right)+\left(\frac{\left(-1\right)+4}{6}\right)\)
= \(\frac{-7}{20}+\frac{1}{2}\)
= \(\frac{-7}{20}+\frac{10}{20}=\frac{\left(7\right)+10}{20}=\frac{3}{20}\)
tk mk nha
đang âm rất nhiều rồi , giúp nha !!!!!
a,-3/5.2/7+-3/7.3/5+-3/7
=-3/7.2/5+(-3/7).3/5+(-3/7)
=-3/7(2/5+3/5+1)
=-3/7.2
=-6/7
a) \(\frac{2}{5}+\left(\frac{3}{4}-\frac{7}{10}\right)\)
\(=\frac{2}{5}+\frac{1}{20}\)
\(=\frac{9}{20}\)
b) \(\frac{-1}{8}-\left(\frac{2}{3}-\frac{11}{12}\right)\)
\(=-\frac{1}{8}-\left(-\frac{1}{4}\right)\)
\(=\frac{1}{8}\)
c) \(\frac{7}{5}-\left(\frac{1}{6}+\frac{9}{10}\right)\)
\(=\frac{7}{5}-\frac{16}{15}\)
\(=\frac{1}{3}\)
d) \(\frac{2}{3}+\left(-\frac{1}{4}\right)+\frac{7}{12}-\left(-\frac{1}{4}\right)-\frac{5}{6}\)
\(=\left(\frac{2}{3}+\frac{7}{12}-\frac{5}{6}\right)+\left(-\frac{1}{4}+\frac{1}{4}\right)\)
\(=\left(\frac{5}{4}-\frac{5}{6}\right)+0\)
\(=\frac{5}{12}\)
e) \(2-\left\{\frac{1}{2}-\left[2-\left(\frac{1}{2}+2\right)-\frac{1}{2}\right]+2\right\}\)
\(=2-\left[\frac{1}{2}-\left(2-\frac{5}{2}-\frac{1}{2}\right)+2\right]\)
\(=2-\left[\frac{1}{2}-\left(-1\right)+2\right]\)
\(=2-\frac{7}{2}\)
\(=-\frac{3}{2}\)