25.9-25.17/-8.80-.10=25.(9-17)/-8(80+10)=25.(-8)/-8.90=25/90=5/18

48.12-48.15/-3.270-3.30=48.(12-15)/-3(270+30)=48.-3/-3.300=48/300=4/25

thông cảm e mới học lớp 6 nên sai thì thôi còn chỗ -3 hay -8 là vì thay -2 lần trừ  ra cộng

 ((25.9 - 25.17))(( - 8.80 - 8.10)) ) và  ((48.12 - 48.15))(( - 3.270 - 3.30)) ). hãy so sánh 2 phân số trên

lấy máy tính ra bấm là nó ra liền à

\(\frac{-35}{280}=\frac{\left(-35\right):35}{280:35}=\frac{-1}{8}\)     

\(\frac{24}{72}=\frac{24:24}{72:24}=\frac{1}{3}\)

\(\frac{15}{-105}=\frac{-15}{105}=\frac{\left(-15\right):15}{105:15}=\frac{-1}{7}\)

\(\frac{36}{240}=\frac{36:12}{240:12}=\frac{3}{20}\)

\(\frac{125}{1000}=\frac{125:125}{1000:125}=\frac{1}{8}\)

\(\frac{198}{126}=\frac{198:18}{126:18}=\frac{11}{7}\)

\(\frac{3}{243}=\frac{3:3}{243:3}=\frac{1}{81}\)

\(\frac{103}{3090}=\frac{103:103}{3090:103}=\frac{1}{30}\)

\(\frac{252525}{535353}=\frac{252525:10101}{535353:10101}=\frac{25}{53}\)

\(\frac{25.9-25.17}{-8.80-8.10}=\frac{25.\left(9-17\right)}{-8.\left(80+10\right)}=\frac{25.\left(-8\right)}{\left(-8\right).90}=\frac{5}{18}\)

\(\frac{25\cdot9-25\cdot17}{-8\cdot80-8\cdot10}=\frac{25\cdot(9-17)}{8\cdot(-80)-8\cdot10}=\frac{25\cdot(-8)}{8\cdot(-80-10)}=\frac{25\cdot(-8)}{8\cdot(-90)}=\frac{5}{18}\)

P/S : Hoq chắc :>

\(\frac{25.9-25.17}{-8.80-8.10}\)= \(\frac{25\left(9-17\right)}{-8\left(80+10\right)}\)= \(\frac{25.\left(-8\right)}{90.\left(-8\right)}\)= \(\frac{25}{90}\)= \(\frac{5}{18}\)

a)2.3.5.13/26.35

=2.3.5.13/2.13.5.7

=3/7

b)18.6-18/-36.(-35)

=18.6-18/-(36.25)=18(6-1)/-(36.35)

=18.5/-(36.35)=2.3.3.5/-(2.2.3.3.5.7)

=-1/14

c)6.4+6.7/6.5+12=6.4+6.7/6.5+6.2

=6(4+7)/6(5+2)

=11/10

d)25.9-25.17/-8.80-8.10=25(9-17)/8(-80-10)

=25.(-8)/8(-90)

=5/18

e) 3⁴.5-3⁶/3⁴.13-3⁴

⁼3⁴(5-3²)/3⁴(13-1)

=5-3²/13-1=-1/3

a/\(\frac{3939-101}{3.2929+505}=\frac{39.101-101}{8787+505}=\frac{101.\left(39-1\right)}{87.101+5.101}=\frac{101.38}{101.\left(87+5\right)}=\frac{38}{92}\)

\(=\frac{38}{92}\)

b/\(\frac{6.4+6.7}{6.5+12}=\frac{4+1.7}{1.5+2}=\frac{4+7}{5+2}=\frac{11}{7}\)

\(\frac{6.4+6.7}{6.5+12}\)\(=\frac{6.4+6.7}{6.5+6.2}\)\(=\frac{6.\left(4+7\right)}{6.\left(5+2\right)}\)\(=\frac{6.11}{6.7}\)\(=\frac{11}{7}\)

a) \(\frac{25.9-25.17}{-8.80-8.10}=\frac{25.\left(9-17\right)}{-8.\left(80+10\right)}=\frac{25.\left(-8\right)}{-8.90}=\frac{5}{18}\)

b) \(\frac{48.12-48.15}{-3.270-3.30}=\frac{48.\left(12-15\right)}{-3.\left(270+30\right)}=\frac{48.\left(-3\right)}{-3.300}=\frac{4}{25}\)

c) \(\frac{2^5.7+2^5}{2^5.5^2-2^5.3}=\frac{2^5.\left(7+1\right)}{2^5.\left(5^2-3\right)}=\frac{2^5.8}{2^5.\left(25-3\right)}=\frac{2^5.8}{2^5.22}=\frac{4}{11}\)

d) \(\frac{3^4.5-3^6}{3^4.13+3^4}=\frac{3^4.\left(5-3^2\right)}{3^4.\left(13+1\right)}=\frac{3^4.\left(5-9\right)}{3^4.14}=\frac{3^4.\left(-4\right)}{3^4.14}=\frac{-2}{7}\)

Nguyễn Lương Bảo Tiên tại sao 

3^4 × 5 - 3^6 lại = 3^4 (5 - 3^2) vậy

phần d ý

à Bảo Tiên lm đúng rồi