\(0,75-0,6+\dfrac{3}{7}+\dfrac{3}{13}-2,75-2,2+\dfrac{11}{7}+\dfrac{11}{13}\\ =\left(0,75-0,6-2,75-2,2\right)+3\cdot\left(\dfrac{1}{7}+\dfrac{1}{13}\right)+11\cdot\left(\dfrac{1}{7}+\dfrac{1}{13}\right)\\ =\left(-4,8\right)+\left(3+11\right)\cdot\dfrac{20}{91}\\ =-4,8+14\cdot\dfrac{20}{91}\\ =-\dfrac{24}{5}+\dfrac{40}{13}\\ =-\dfrac{112}{65}\)

0,75-0,6+\(\frac{3}{7}+\frac{3}{\frac{13}{2,75}}\) -2,2+\(\frac{11}{7}\) +\(\frac{11}{13}\)

=\(\frac{3}{4}-\frac{3}{5}+\frac{3}{7}+\frac{11}{16}-\frac{11}{5}+\frac{11}{7}+\frac{11}{3}\)

= \(\left(\frac{11}{16}+\frac{3}{4}\right)+\left[\left(\frac{-3}{5}\right)-\frac{11}{5}\right]+\left(\frac{3}{7}+\frac{11}{7}\right)+\frac{11}{3}\)

= \(\frac{23}{16}-\frac{14}{5}+2+\frac{11}{3}\)

=\(\left(\frac{23}{16}+2\right)+\left[\left(\frac{-14}{5}\right)+\frac{11}{3}\right]\)

=\(\frac{55}{16}+\frac{13}{15}\)

\(\approx\) 4,3

chúc bạn học good (like nink nha)

cái gì vậy

67,8 nhớ k đấy

= sửa thành + nhé

\(\frac{0,75+0,6-\frac{3}{7}-\frac{3}{13}}{2,75+2,2-\frac{11}{7}-\frac{11}{13}}\)

\(=\frac{\frac{3}{4}+\frac{3}{5}-\frac{3}{7}-\frac{3}{13}}{\frac{11}{4}+\frac{11}{5}-\frac{11}{7}-\frac{11}{13}}\)

\(=\frac{3.\left(\frac{1}{4}+\frac{1}{5}-\frac{1}{7}-\frac{1}{13}\right)}{11.\left(\frac{1}{4}+\frac{1}{5}-\frac{1}{7}-\frac{1}{13}\right)}\)

\(=\frac{3}{11}\)

\(\frac{0,75-0,6-\frac{3}{7}+\frac{3}{13}}{2,75+2,2-\frac{11}{7}-\frac{11}{13}}\)

\(=\frac{\frac{3}{4}-\frac{3}{5}+\frac{3}{7}+\frac{3}{13}}{\frac{11}{4}-\frac{11}{5}+\frac{11}{7}+\frac{11}{13}}\)

\(=\frac{3.\left(\frac{1}{4}-\frac{1}{5}+\frac{1}{7}+\frac{1}{13}\right)}{11.\left(\frac{1}{4}-\frac{1}{5}+\frac{1}{7}+\frac{1}{13}\right)}\)

\(=\frac{3}{11}\)

 P = 0,75 - 0,6 +3/7 + 3/13

= 3/4 - 3/5 +3/7 +3/13

= \(\frac{1365-1092+780+420}{1820}\)

=1473

trên có nghĩa là dấu gạch ngang ở giữa

3/4-3/5+3/7+3/13 trên 11/4-11/5+11/7+11/3=3x1/4-3x1/5+3x1/7+3x1/13 trên 11x1/4-11x1/5+11x1/7+11x1/13=3x(1/4-1/5+1/7+1/13) trên 11x(1/4-1/5+1/7+1/13)=3/11

vay P=3/11