tính giá trị biểu thức sau ( tính nhanh nếu cs thể ) 6/7 + 5/8 : 5 – 3/16 . ( – 2 )^2 2/3 + 1/3 . [ -4/9 + 5/6 ] : 7/12

0 bình luận về “tính giá trị biểu thức sau ( tính nhanh nếu cs thể ) 6/7 + 5/8 : 5 – 3/16 . ( – 2 )^2 2/3 + 1/3 . [ -4/9 + 5/6 ] : 7/12”

1. `a)` $\dfrac{6}{7}$+$\dfrac{5}{8}$ `: 5 -` $\dfrac{3}{16}$ `.` $(-2)^{2}$ 

   `=` $\dfrac{6}{7}$`+`$\dfrac{5}{8}$ `.` $\dfrac{1}{5}$ `-` $\dfrac{3}{16}$ `.` `4`

   `=` $\dfrac{6}{7}$`+`$\dfrac{1}{8}$ `-` $\dfrac{3}{4}$

   `=` $\dfrac{48}{56}$`+`$\dfrac{7}{56}$ `-` $\dfrac{42}{56}$

   `=` $\dfrac{13}{56}$

   `b)` $\dfrac{2}{3}$ `+` $\dfrac{1}{3}$ `. [` $\dfrac{-4}{9}$ `+` $\dfrac{5}{6}$ `]` `:` $\dfrac{7}{12}$

   `=` $\dfrac{2}{3}$ `+` $\dfrac{1}{3}$ `. [` $\dfrac{-16}{36}$ `+` $\dfrac{30}{36}$ `]` `:` $\dfrac{7}{12}$

   `=` $\dfrac{2}{3}$ `+` $\dfrac{1}{3}$ `.` $\dfrac{7}{18}$ `:` $\dfrac{7}{12}$

   `=` $\dfrac{2}{3}$ `+` $\dfrac{7}{54}$ `:` $\dfrac{7}{12}$

   `=` $\dfrac{2}{3}$ `+` $\dfrac{6}{27}$

   `=` $\dfrac{25}{27}$

   Trả lời

2. 2/3+1/3. [-4/9 + 5/6 ] : 7/12

   2/3 + 1/3 . 7/18 : 7/12

   (2/3 + 1/3) . 84/126

   (2/3 + 1/3) . 2/3

   1 . 2/3

   =2/3

    

   Trả lời