Question

[luu khanh van]

1.Thực hiện phép tính bằng cách hợp lí

a)\(-\dfrac{4}{9}+\left(-\dfrac{5}{6}\right)-\dfrac{17}{4}\) b)\(5\dfrac{1}{2}+\left(-3\right)\) c)\(4\dfrac{9}{11}+\left(-2\dfrac{1}{11}\right)\)

2.tính

a)4,3 - (1,2) b) 0 - (-0,4) c) \(-\dfrac{2}{3}-\dfrac{1}{3}\) d) \(-\dfrac{1}{2}-\dfrac{-1}{6}\)

Mong mọi người giải dùm mình , mình cần gấp lắm

Answer 1

[Diễm Quỳnh]

1.

a) \(-\dfrac{4}{9}+\left(-\dfrac{5}{6}\right)-\dfrac{17}{4}=-\dfrac{16}{36}-\dfrac{30}{36}-\dfrac{153}{36}\)

\(=-\dfrac{199}{36}\)

b) \(5\dfrac{1}{2}+\left(-3\right)=5\dfrac{1}{2}-3=\dfrac{11}{2}-\dfrac{6}{2}=\dfrac{5}{2}\)

c) \(4\dfrac{9}{11}+\left(-2\dfrac{1}{11}\right)=\dfrac{53}{11}-\dfrac{23}{11}=\dfrac{30}{11}\)

Answer 2

[Diễm Quỳnh]

2.

a) \(4,3-\left(1,2\right)=3,1\)

b) \(0-\left(-0,4\right)=0+0,4=0,4\)

c) \(-\dfrac{2}{3}-\dfrac{1}{3}=-\dfrac{3}{3}=-1\)

d) \(-\dfrac{1}{2}-\dfrac{-1}{6}=-\dfrac{1}{2}+\dfrac{1}{6}=-\dfrac{3}{6}+\dfrac{1}{6}=-\dfrac{2}{6}=-\dfrac{1}{3}\)