phân số thứ 2 ở trên tử số\(5^3\) thành \(5^2\) nha

\(\dfrac{a}{b}=\dfrac{3^4\cdot2^2\cdot\left(2-1\right)}{3^5\cdot\left(3^2-5\right)}=\dfrac{2^2}{3}\cdot\dfrac{1}{4}=\dfrac{1}{3}\)

\(\dfrac{c}{d}=\dfrac{5^3\left(7-2\right)}{5^3\left(7-4\right)}=\dfrac{5}{3}\)

Do đó: a/b<c/d

1857 nha bạn tính máy tính là ra

1857 nha bạnnnnnnn!

\(\frac{3^4.2^3-3^4.4}{3^5.3^2-3^5.5}=\frac{3^4.\left(2^3-4\right)}{3^5.\left(3^2-5\right)}=\frac{8-4}{3.\left(9-5\right)}=\frac{4}{3.4}=\frac{1}{3}\)

\(\frac{3^4\cdot2^3-3^4\cdot4}{3^5.3^2-3^5\cdot5}=\frac{3^4\left(8-4\right)}{3^5\left(9-5\right)}=\frac{4}{3\cdot4}=\frac{1}{3}\)

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

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

Câu 1:

A = \(\frac{25.9-25.17}{-8.80-8.10}\)

A = \(\frac{25.\left(9-17\right)}{-8.10\left(8+1\right)}\)

A = \(\frac{5.5.\left(-8\right)}{-8.10.9}\)

A = \(\frac{5.5.2.4}{2.4.5.2.9}\)

A = \(\frac{5}{18}\)

B = \(\frac{48.12-48.15}{-3.270-3.30}\)

B = \(\frac{48.\left(12-15\right)}{-3.30\left(9+1\right)}\)

B = \(\frac{6.8.\left(-3\right)}{-3.30.10}\)

B = \(\frac{6.2.4.\left(-3\right)}{-3.5.6.2.5}\)

B = \(\frac{4}{25}\) = \(\frac{20}{125}\) < \(\frac{20}{72}\) = \(\frac{5}{18}\)

A > B

Câu 2:

A = \(\frac{2^5.7+2^5}{2^5-2^5.3}\)

A = \(\frac{2^5.\left(7+1\right)}{2^5-2^5.3}\)

A = \(\frac{2^5.8}{2^5.\left(1-3\right)}\)

A = \(\frac{8}{-2}\)

A = -4

B = \(\frac{3^4.5-3^6}{3^4.13+3^4}\)

B = \(\frac{3^4.\left(1-3^2\right)}{3^4.\left(13+1\right)}\)

B = \(\frac{1-9}{14}\)

B = \(\frac{-8}{14}\)

B = \(\frac{-4}{7}\) > - 4

Vậy A < B

5² - (5 . 3³ - 4 . 2³) .19

= 25 - (5 . 27 - 4 . 8) .19

= 25 - (135 - 32) .19

= 25 - 103 .19

= 25 - 1957

= -1932

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

a , 5.6 + 5.7 / 5.8 + 20 = 5.6 + 5.7 / 5.8 + 5 . 4 = 5 . ( 6+7 ) / 5 . ( 8 + 4 ) = 6 + 7 / 8 + 4 = 13 / 12                                                                8 . 9 + 4 .15 / 12 . 7 - 180 = 4 . 2 . 3 . 3 + 2 . 2 . 3 . / 4 . 3 . 7 - 180 = 4 . 2 . 3 . 3 + 2.2.3.5 / 3 . 4 . 7 - 3 . 2 . 2 . 3. 5 = 1 . 2 . 1 . 1 + 1 . 1 . 1. 1 / 1 . 1 . 7 - 1 . 1 . 1 . 1 .1 = 3 / 6 = 1/2                                                                                                                                                      b , 2^5 . 7 +2^5 / 2^5 . 5^2 - 2^5 .3  = 2^5 . ( 7 + 1) / 2^5 ( 5^2 - 3 ) = 7+1 / 5^2 - 3 = 8 / 22 = 4 / 11                                                           3^4 . 5 - 3^6 / 3^4 . 13 + 3^4 = 3^4 . 5 - 3^4 . 3^2  / 3^4 . 13 + 3^4 = 3^4 . ( 5 - 3^2 ) / 3^4 . ( 13 + 1 ) = 5 - 3^2 / 13 + 1 = -4 / 14 = -2 / 12