thực hiện phép tính
)
−0,8:(45.1,25)0,64−15−0,8:(45.1,25)0,64−15
b) ( 13,71 - 156156 ) . 6 - 6 . 13 . 17
c) (35+0,415+1200):0,0130,75+112+316(35+0,415+1200):0,0130,75+112
Tìm x, biết: 1 12 + 3 1 6 - 30 , 75 . x - 8 = 3 5 + 0 , 415 + 1 200 : 0 , 01
Ta có:
= (0,6 + 0,415 + 0,005) : 0,01 = 1,02 : 0,01 = 102.
Biểu thức trở thành:
Vậy x = -4.
Thực hiện phép tính
a) \(\dfrac{-0,8:\left(\dfrac{4}{5}.1,25\right)}{0,64-\dfrac{1}{5}}\)
b) ( 13,71 - \(1\dfrac{5}{6}\) ) . 6 - 6 . 13 . 17
c) \(\dfrac{\left(\dfrac{3}{5}+0,415+\dfrac{1}{200}\right):0,01}{30,75+\dfrac{1}{12}+3\dfrac{1}{6}}\)
a) \(\dfrac{-0.8:\left(\dfrac{4}{5}\cdot1.25\right)}{0.64-\dfrac{1}{5}}=\dfrac{\dfrac{-4}{5}:\left(\dfrac{4}{5}\cdot\dfrac{5}{4}\right)}{\dfrac{16}{25}-\dfrac{1}{5}}=\dfrac{\dfrac{-4}{5}:1}{\dfrac{16}{25}-\dfrac{5}{25}}=\dfrac{\dfrac{-4}{5}}{\dfrac{11}{25}}=\dfrac{-4}{5}\cdot\dfrac{25}{11}=\dfrac{-20}{11}\)
b) \(\left(13.71-1\dfrac{5}{6}\right)\cdot6-6\cdot13\cdot17=\left(\dfrac{1371}{100}-\dfrac{11}{6}\right)\cdot6-6\cdot13\cdot17=\dfrac{3563}{300}\cdot6-6\cdot13\cdot17=\dfrac{3563}{50}-6\cdot13\cdot17=\dfrac{3563}{50}-1326=\dfrac{-62737}{50}\)
c) \(\dfrac{\left(\dfrac{3}{5}+0.415+\dfrac{1}{200}\right):0.01}{30.75+\dfrac{1}{12}+3\dfrac{1}{6}}=\dfrac{\left(\dfrac{3}{5}+\dfrac{83}{200}+\dfrac{1}{200}\right):\dfrac{1}{100}}{\dfrac{123}{4}+\dfrac{1}{12}+\dfrac{19}{6}}=\dfrac{\dfrac{51}{50}:\dfrac{1}{100}}{34}=\dfrac{102}{34}=3\)
Bài 5 : Tính bằng cách thuận tiện nhất
a, 1,25 x 10,8 x 0,8 : 0,9 b, 0,64 x 0,04 x 25 : 0,8 + 0,5 x 0, 112
c, 28,35 : 0,125 + 42,65 : 0,125 + 1: 0,125
c, 28,35: 0,125 + 42,65: 0,125 + 1:0,125
= (28,35 + 42,65 + 1) : 0,125
= 72 : 0,125
= 72 x 8
= 576
a, 1,25 x 10,8 x 0,8:0,9
= (1,25 x 0,8) x (10,8 :0,9)
= 1 x 12
= 12
b, 0,64 x 0,04 x 25 : 0,8 + 0,5 x 0,112
= (0,64 : 0,8) x (0,04 x 25) + 0,056
= 0,8 x 1 + 0,056
= 0,8 + 0,056
= 0,856
0,8:(4/5.1,25) / 0,64-1/25 + (100-2/5):4/7 / (59/9-13/43):35/17 + (1,2.0,5):3/5
Thực hiện phép tính một cách hợp lí:
\(\frac{0,8:\left(\frac{4}{5}.1,25\right)}{0,64-\frac{1}{25}}+\frac{\left(1,08-\frac{2}{25}\right):\frac{4}{7}}{\left(6\frac{5}{9}-3\frac{1}{4}\right).2\frac{2}{17}}\)
Thực hiện phép tính: E =\(\frac{0,8:\left(\frac{4}{5}.1,25\right)}{0,64-\frac{1}{25}}+\frac{\left(1,08-\frac{2}{25}\right):\frac{4}{7}}{\left(6\frac{5}{9}-3\frac{1}{4}\right).2\frac{2}{17}}\)+ (1,2 . 0,5 ) : \(\frac{4}{5}\)
$B=\frac{\left(\frac{11^2}{200}+0,415\right):0.01}{\frac{1}{12}-37,25+3\frac{1}{6}}$B=
(
112
200 +0,415):0.01
1
12 −37,25+3
1
6
giúp em với !!
Thực hiện phép tính: E =\(\frac{0,8:\left(\frac{4}{5}.1,25\right)}{0,64-\frac{1}{25}}+\frac{\left(1,08-\frac{2}{25}\right):\frac{4}{7}}{\left(6\frac{5}{9}-3\frac{1}{4}\right).2\frac{2}{17}}\)+ (1,2 . 0,5 ) : \(\frac{4}{5}\)
\(E=\frac{0,8:\left(\frac{4}{5}.1,25\right)}{0,64-\frac{1}{25}}+\frac{\left(1,08-\frac{2}{25}\right):\frac{4}{7}}{\left(6\frac{5}{9}-3\frac{1}{4}\right).2\frac{2}{17}}+\left(1,2.0,5\right):\frac{4}{5}\)
\(E=\frac{\frac{4}{5}:\frac{4}{5}:1,25}{\frac{16}{25}-\frac{1}{25}}+\frac{\left(\frac{27}{25}-\frac{2}{25}\right).\frac{7}{4}}{\left(\frac{59}{9}-\frac{13}{4}\right).\frac{36}{17}}+\frac{6}{5}.\frac{1}{2}.\frac{5}{4}\)
\(E=\frac{1:\frac{5}{4}}{\frac{3}{5}}+\frac{1.\frac{7}{4}}{\frac{119}{36}.\frac{36}{17}}+\frac{3}{4}\)
\(E=\frac{4}{5}.\frac{5}{3}+\frac{\frac{7}{4}}{7}+\frac{3}{4}\)
\(E=\frac{4}{3}+\frac{7}{4}.\frac{1}{7}+\frac{3}{4}\)
\(E=\frac{4}{3}+\frac{1}{4}+\frac{3}{4}\)
\(E=\frac{4}{3}+1=\frac{7}{3}\)
Tinh :
{112/200+0,415}:0,01
1/2-37,25+3-1/6
{\(\frac{112}{200}\)+ 0,415} : 0,01
= {\(\frac{112}{200}+\frac{415}{1000}\)} : \(\frac{1}{100}\)
={\(\frac{560}{1000}\)+\(\frac{415}{1000}\)} : \(\frac{1}{100}\)
=\(\frac{975}{1000}\): \(\frac{1}{100}\)
=\(\frac{975}{1000}\)x\(\frac{100}{1}\)
=\(\frac{97500}{1000}\)=\(97,5\)
\(\frac{1}{2}-37,5+3-\frac{1}{6}\)
=\(\frac{1}{2}-\frac{375}{10}+\frac{3}{1}-\frac{1}{6}\)
=\(\frac{15}{30}-\frac{1125}{30}+\frac{90}{30}-\frac{5}{30}\)
=\(\frac{15-1125+90-5}{30}\)
=\(\frac{\left(-1110\right)+85}{30}\)
=\(\frac{-1025}{30}\)
Mik ko chắc!!!