`= 4/16+3/2-5/4`

`= 7/4-5/4=2/4=1/2`

C. Ai thế nào?

If you study hard, you won'f fail the exam.

\(3\times145+3\times\dfrac{55}{6}\times215+6\times85\)

\(=3\times145+3\times\dfrac{55}{6}\times215+3\times2\times85\)

\(=3\times\left(145+\left(\dfrac{55}{6}\times215\right)+\left(2\times85\right)\right)\)

\(=3\times\left(145+\dfrac{11825}{6}+170\right)\)

\(=3\times\dfrac{13715}{6}=6857,5\)

\(\cdot N\)

\(\dfrac{7}{8}\times2\div\dfrac{7}{4}=\dfrac{7}{4}\div\dfrac{7}{4}=\dfrac{7}{4}\times\dfrac{4}{7}=1\)

#\(N\)

\(x+7,78=11,34\)

\(x=11,34-7,78\)

\(x=3,56\)

\(\dfrac{3}{16}+4=\dfrac{3}{16}+\dfrac{64}{16}=\dfrac{67}{16}\)

#\(N\)

`1=5/5`→ `4/5 <1`

`1=9/9`→`16/9>1`

`1= 10/10`→`99/10 > 1`

`1=81/81`→` 78/81 <1`

\(\cdot DuyNam\)

`= (1,5 + 8,5) + (2,5 + 7,5) + (3,5 + 6,5) + (4,5 +5,5)`

`= 10+10+10+10`

`=40`