Question

Tính bằng cách hợp lí (nếu có thể):

giúp mình với mình đang cần gấppp ạ

Answer 1

\(a,=-17+91-91+17+2011=\left(-17+17\right)+\left(91-91\right)+2011\)

\(=0+0+2011=2011\)

 

Answer 2

b)\(=\dfrac{4}{7}+\dfrac{1}{6}-0,375.4=\dfrac{31}{42}-\dfrac{3}{2}=-\dfrac{16}{21}\)

 

Answer 3

\(b)\) \(\dfrac{4}{7}\) + \(\dfrac{5}{6}\) : \(5\) \(- 0,375 .(-2)\)²\(=\) \(\dfrac{4}{7}\) + \(\dfrac{1}{6}\) - \(0,375\) . \(4\)

= \(\dfrac{4}{7}\) + \(\dfrac{1}{6}\) - \(\dfrac{3}{2}\) = \(\dfrac{4.6}{42}\) +  \(\dfrac{1.7}{42}\) - \(\dfrac{3.21}{42}\) = \(-\)\(\dfrac{16}{21}\)

Answer 4

\(c)\) = \((\) \(\dfrac{-7}{11}\) + \(\dfrac{-4}{11}\) \()\) . \(\dfrac{12}{5}\) . \(\dfrac{2.5}{3}\)

    = \((-1).8=-8\)

Answer 5

c)\(=\left[\left(\dfrac{-7}{11}+\dfrac{-4}{12}\right)\times\dfrac{5}{12}\right]\cdot\dfrac{2.5}{3}\)

\(=\left[-\dfrac{32}{33}\times\dfrac{12}{5}\right]\cdot\dfrac{10}{3}=-\dfrac{128}{55}\times\dfrac{10}{3}=-\dfrac{256}{33}\)