\(15,3:\left(1+0,25\times16\right)\)

\(=15,3:\left(1+4\right)\)

\(=15,3:5\)

\(=3,06\)

thanks siu

\(\dfrac{2}{5}\times\dfrac{2}{7}+\dfrac{2}{5}\times\dfrac{5}{7}+\dfrac{2}{5}\times9\)

\(=\dfrac{2}{5}\times\left(\dfrac{2}{7}+\dfrac{5}{7}+9\right)\)

\(=\dfrac{2}{5}\times10\)

\(=4\)

20

Số đó là:

\(42:75\%=42\times\dfrac{100}{75}=56\)

Đ/S:..

56

\(\dfrac{11}{19}.\dfrac{12}{29}-\dfrac{11}{19}.\dfrac{2}{29}+\dfrac{11}{19}.\dfrac{19}{29}\)

\(=\dfrac{11}{19}.\left(\dfrac{12}{29}-\dfrac{2}{29}+\dfrac{19}{29}\right)\)

\(=\dfrac{11}{19}.1\)

\(=\dfrac{11}{19}\)

Thời gian để xe đến B là 10h45 -7h45=10,75-7,25=3,5 ( giờ)

Độ dài quãng đường AB là3,5×14=49km

Tick cho mk nhé>.<

bài hơi vô lý 

\(0,12\times x=6\)

            \(x=6:0,12\)

            \(x=50\)

\(x\times0,1=\dfrac{2}{5}\)

\(x=\dfrac{2}{5}:0,1\)

\(x=\dfrac{2}{5}\times10\)

\(x=4\)

X = 6 : 0,12

X = 50