Câu 1: C
Câu 2: B
Câu 3: C
Câu 4: A
Câu 6:
\(3\dfrac{2}{5}+4\dfrac{3}{7}-\dfrac{1}{4}+\dfrac{44}{77}-2\dfrac{2}{5}-0,75\)
\(=\dfrac{17}{5}+\dfrac{31}{7}-\dfrac{1}{7}+\dfrac{4}{7}-\dfrac{12}{5}-\dfrac{3}{4}\)
\(=\left(\dfrac{17}{5}-\dfrac{12}{5}\right)+\left(\dfrac{31}{7}+\dfrac{4}{7}\right)+\left(-\dfrac{1}{4}-\dfrac{3}{4}\right)\)
\(=1+5+\left(-1\right)\)
\(=5\)
~ HỌC TỐT ~ TIK MIK NHA ~
Câu 6:
\(3\dfrac{2}{5}+4\dfrac{3}{7}-\dfrac{1}{4}+\dfrac{44}{77}-2\dfrac{2}{5}-0,75\)
\(=\dfrac{17}{5}+\dfrac{31}{7}-\dfrac{1}{7}+\dfrac{44}{77}-\dfrac{12}{5}-\dfrac{3}{4}\)
\(=5\)
C1 : D
C2 : B
C3 : C
C4 : A
C5 : D ( K chắc lắm )
C6 :
\(3\dfrac{2}{5}+4\dfrac{3}{7}-\dfrac{1}{4}+\dfrac{44}{77}-2\dfrac{2}{5}-0,75\)
\(=\dfrac{17}{5}+\dfrac{31}{7}-\dfrac{1}{4}+\dfrac{4}{7}-\dfrac{12}{5}-\dfrac{3}{4}\)
\(=\left(\dfrac{17}{5}-\dfrac{12}{5}\right)+\left(\dfrac{31}{7}+\dfrac{4}{7}\right)+\left(-\dfrac{1}{4}-\dfrac{3}{4}\right)\)
\(=1+5\) + ( -1)
= 5
