\(\frac{2130-15}{\left(-3550\right)+20}=\frac{2115}{-3520}=-\frac{423}{704}\)

a) \(\frac{2.7.13}{26.35}=\frac{2.7.13}{2.13.5.7}=\frac{1}{5}\)

b) \(\frac{23.5-23}{4-27}=\frac{23.\left(5-1\right)}{-23}=\frac{23.4}{-23}=\frac{23.\left(-4\right)}{23}=-4\)

c) \(\frac{2130-15}{3550-25}=\frac{142.15-15}{142.25-25}=\frac{15.\left(142-1\right)}{25.\left(142-1\right)}=\frac{15.141}{25.141}=\frac{15}{25}=\frac{3.5}{5.5}=\frac{3}{5}\)

d) \(\frac{1717-101}{2828+404}=\frac{17.101-101}{28.101+101.4}=\frac{101.\left(17-1\right)}{101.\left(28+4\right)}=\frac{101.16}{101.32}=\frac{16}{32}=\frac{4.4}{2.4.4}=\frac{1}{2}\)

e) \(\frac{3.5.11.13}{33.35.27}=\frac{3.5.11.13}{3.11.5.7.3^3}=\frac{13}{7.3^3}=\frac{13}{189}\)

f) \(\frac{85-17+34}{51-102}=\frac{5.17-17+2.17}{3.17-6.17}=\frac{17.\left(5-1+2\right)}{17.\left(3-6\right)}=\frac{17.6}{17.\left(-3\right)}=\frac{6}{-3}=-2\)

cho mik hỏi tại sao lại trừ với 1 ạ

a)  2 5 + 3 6 = 12 30 + 15 30 = 27 30 = 9 10

b)  21 30 - 9 30 = 12 30 = 2 5

c)  5 8 × 4 7 = 20 56 = 5 14

d)  7 9 ÷ 11 6 = 7 9 × 6 11 = 42 99 = 14 33

a,481/259 + 234/585 + -51/85

=13/7+2/5+-3/5

=13/7 + -1/5

=58/35

c,1616/3232-70/105+186/217

=1/2-2/3+6/7

= -1/6+6/7

=29/42

d,125/-150 + -108/126 - 448/-640

= -5/6 + -6/7 - -7/10

= -71/42 - -7/10

= -104/105

xin lỗi bạn nhưng mình ko biết làm phần b