Bài 1 : Cho\(\frac{1}{2}a=\frac{3}{4}b\) và a-b=4,5 .tìm a,b
Bài 2: Tính
\(a,-\frac{3}{4}+\frac{3}{4}\div\frac{3}{5}\)
\(b,\frac{5}{6}-\left(\frac{5}{6}+\frac{1}{3}\right)-\frac{1}{2}\)
\(c,1\div\left(1-\frac{1}{2}\right)^2\)
Bài 7: Tính giá trị biểu thức:
a) A = \(\left(\frac{\frac{1}{4}-\frac{1}{4}+\frac{1}{9}}{\frac{1}{9}}\right):\left(\frac{\frac{2}{3}+\frac{7}{15}}{\frac{2}{5}-\frac{1}{6}}\right)\)
b) B = (0,8.7+0,64).(1,25.7-\(\frac{4}{6}\).1,25) +31,64
Bài 7: Tính giá trị biểu thức:
a) A=( \(\frac{1}{4}-\frac{1}{4}+\frac{1}{9}:\frac{1}{9}\)) : (\(\frac{2}{3}+\frac{7}{15}:\frac{2}{5}-\frac{1}{6}\))
b) B = (0,8.7+0,64).(1,25.7-\(\frac{4}{6}\).1,25) +31,64
tính :
a) \(\frac{4}{9}:\frac{-1}{7}+6\frac{5}{9}:\frac{-1}{7}\)
b) \(\left(2\frac{1}{3}+3\frac{1}{2}\right):\left(-4\frac{1}{6}+3\frac{1}{7}\right)+7\frac{1}{2}\)
c) \(\frac{\left(13\frac{1}{4}-2\frac{5}{27}-10\frac{5}{6}\right).230\frac{1}{25}+46\frac{3}{4}}{\left(1\frac{3}{7}+\frac{10}{3}\right):\left(12\frac{1}{3}-14\frac{2}{7}\right)}\)
\(a,\left|x-\frac{2}{5}\right|=0,5-\left(-\frac{1}{2}\right)\)
\(b,\frac{3}{2}\left|\frac{1}{4}-x\right|=\frac{5}{6}-1\)
\(c,\frac{4}{3}-\frac{5}{3}\left|x-\frac{1}{3}\right|=-\frac{1}{6}\div\frac{2}{3}\)
Tìm x \(\in\) Z biết:
a) \(\frac{1}{2}-\left(\frac{1}{3}+\frac{1}{4}\right)< x< \frac{1}{48}-\left(\frac{1}{16}-\frac{1}{6}\right)\) b) \(4\frac{5}{9}:2\frac{5}{18}-7< x< \left(3\frac{1}{5}:3,2+4,5.1\frac{31}{45}\right):\left(-21\frac{2}{3}\right)\)Cho và . Khi đó ...
Tính hợp lí:
a) \(A=\left(\frac{3}{4}-\frac{4}{7}-\frac{5}{6}\right):\left(-\frac{3}{10}+\frac{4}{14}-\frac{-5}{12}\right)\left(\frac{1}{12}-\frac{7}{6}\right)\)
b) 123.(-234+4356-2312)+234.(123-2312)-2312.(-234-123)
1. Tính hợp lí :
a) \(\frac{3}{4}-0,25-\left[\frac{7}{3}+\left(\frac{-9}{2}\right)\right]-\frac{5}{6}\)
b) 7 + \(\left(\frac{7}{12}-\frac{1}{2}+3\right)-\left(\frac{1}{12}+5\right)\)
2. Tìm các sô nguyên x biết:
\(\frac{3}{4}-\frac{5}{6}\le\frac{x}{12}< 1-\left(\frac{2}{3}-\frac{1}{4}\right)\)