\(\frac{3^4\cdot5-3^6}{3^4\cdot13+3^4}=\frac{3^4\cdot5-3^2\cdot3^4}{3^4\cdot13+3^4}=\frac{5-3^2}{13}=\frac{5-9}{13}=\frac{-4}{13}\)

Chắc là vậy đó

\(\frac{3^4.5-3^6}{3^4.13+3^4}=\frac{3^4.5-3^4.3^2}{3^4.\left(13+1\right)}=\frac{3^4.\left(5-9\right)}{3^4.14}=-\frac{4}{14}=-\frac{2}{7}\)

Ta có: \(\frac{2^5.7+2^5}{2^5.5^2-2^5.3}\) = \(\frac{2^5.\left(7+1\right)}{2^5.\left(5^2-3\right)}\) = \(\frac{2^5.8}{2^5.22}\) = \(\frac{8}{22}\) =\(\frac{56}{154}\)

​\(\frac{3^4.5-3^6}{3^4.13+3^4}\) = \(\frac{3^4.\left(5-3^2\right)}{3^4.\left(13+1\right)}\) = \(\frac{3^4.\left(-4\right)}{3^4.14}\) = \(\frac{-4}{14}\)= \(\frac{-44}{154}\)

Xét: 2^5x7+2^5/2^5.5^2-2^5.3

=2^5x7+2^5x1/2^5x25-2^5x3

=2^5x(7+1)/2^5x(25-3)

=2^5x8/2^5x22

=8/22

=4/11

Xét: 3^4x5-3^6/3^4x13+3^4

=3^4x5-3^4x3^2/3^4x13+3^4

=3^4x(5-9)/3^4x(13+1)

=3^4x(-4)/3^4x14

=-4/14

=-2/7

Mẫu số chung của 4/11 và -2/7 là 77

-->Thừa số phụ tương ứng là 7 và 11

Quy đồng : 4/11=4x7/11x7=28/77

                -2/11=(-2)x11/7x11=-22/77

Vậy ta có 28/77 và -22/77

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