a) 36:(-6)<0

b) (-15):(-3)>(-63):7

Câu 4:

\(4^{n+2}-4^{n-1}=252\\ \Leftrightarrow4^{n-1}.\left(4^3-1\right)=252\\ \Leftrightarrow4^{n-1}.63=252\\ \Leftrightarrow4^{n-1}=\dfrac{252}{63}=4=4^1\\ \Rightarrow n-1=1\\ \Rightarrow n=2\)

Câu 7:

\(\left(\dfrac{36}{49}\right)^4:\left(-\dfrac{6}{7}\right)^6=\left(\dfrac{6}{7}\right)^{2.4}:\left(\dfrac{6}{7}\right)^6=\left(\dfrac{6}{7}\right)^8:\left(\dfrac{6}{7}\right)^6=\left(\dfrac{6}{7}\right)^{8-6}=\left(\dfrac{6}{7}\right)^2=\dfrac{36}{49}\)

Câu 8:

\(13^{96}=\left(13^3\right)^{32}=2197^{32}\\ 15^{64}=\left(15^2\right)^{32}=225^{32}\\ Vì:2197^{32}>225^{32}\left(Do:2197>225\right)\Rightarrow13^{96}>15^{64}\)

a: 6/7=1-1/7

5/6=1-1/6

mà -1/7>-1/6

nên 6/7>5/6

b: 11/10>1>10/11

c: 18/36=3/6<7/6

6/7 bé hơn 5/6

11/10 lớn hơn 10/11

18/36 bé hơn 7/6

Ta có: \(\dfrac{6}{7}=\dfrac{6\times6}{7\times6}=\dfrac{36}{42};\dfrac{5}{6}=\dfrac{5\times7}{6\times7}=\dfrac{35}{42}\)

\(\Rightarrow\dfrac{36}{42}>\dfrac{35}{42}\)

\(\Rightarrow\dfrac{6}{7}>\dfrac{5}{6}\)

Ta có: \(\dfrac{11}{10}=\dfrac{11\times11}{10\times11}=\dfrac{121}{110};\dfrac{10}{11}=\dfrac{10\times10}{11\times10}=\dfrac{100}{110}\)

\(\Rightarrow\dfrac{121}{110}>\dfrac{100}{110}\)

\(\Rightarrow\dfrac{11}{10}>\dfrac{10}{11}\)

Ta có: \(\dfrac{18}{36}\) giữ nguyên ; \(\dfrac{7}{6}=\dfrac{7\times6}{6\times6}=\dfrac{42}{36}\)

\(\Rightarrow\dfrac{18}{36}< \dfrac{42}{36}\)

\(\Rightarrow\dfrac{18}{36}< \dfrac{7}{6}\)

18/36 và 7/6

rút gọn phấn số 18/36 = 3/6

vậy 3/6 < 7/6 hoặc 18/36 < 7/6

18/26=1/2

1/2<1

7/6>1

1/2<7/6

HT

Ta có : \(\frac{18}{36}=\frac{3.6}{6.6}=\frac{3}{6}\)

\(\frac{3}{6}< \frac{7}{6}\)

\(\Rightarrow\frac{18}{36}< \frac{7}{6}\)

Hoặc 

\(\frac{18}{36}< 1\left(18< 36\right)\)

\(\frac{7}{6}>1\left(7>6\right)\)

\(\Rightarrow\frac{18}{36}< \frac{7}{6}\)

HT

6/8>5/7

9/15=3/5

24/36<75/100

\(\dfrac{6}{8}\) ....\(\dfrac{5}{7}\)

\(\dfrac{6}{8}=\dfrac{30}{40}\);  \(\dfrac{5}{7}\)  = \(\dfrac{30}{42}\)

Vì  \(\dfrac{30}{40}\)  > \(\dfrac{30}{42}\) nên \(\dfrac{6}{8}\) > \(\dfrac{5}{7}\)

\(\dfrac{9}{15}\) ....\(\dfrac{3}{5}\)

\(\dfrac{9}{15}\) = \(\dfrac{9:3}{15:3}\) = \(\dfrac{3}{5}\)

Vậy \(\dfrac{9}{15}\) = \(\dfrac{3}{5}\)

\(\dfrac{24}{36}\) ....\(\dfrac{75}{100}\)

\(\dfrac{24}{36}\) = \(\dfrac{24:12}{36:12}\) = \(\dfrac{2}{3}\) = 1 - \(\dfrac{1}{3}\);              \(\dfrac{75}{100}\) = \(\dfrac{75:25}{100:25}\) = \(\dfrac{3}{4}\) = 1 - \(\dfrac{1}{4}\)

vì \(\dfrac{1}{3}\) > \(\dfrac{1}{4}\) nên     1 - \(\dfrac{1}{3}\) < 1 - \(\dfrac{1}{4}\)

Vậy \(\dfrac{24}{36}\) < \(\dfrac{75}{100}\)

6/8>5/7

9/15=3/5

24/36<75/100

❤❤❤

>1/4+1/4+1/16+1/16+1/16

=2/4+3/16=11/16=66/96<80/96=5/6

vậy A<5/6

a: 6^9=(6^3)^3=216^3>15^3

B: 6^36=(6^2)^18=36^18>35^18

c: 7^18=(7^2)^9=49^9>30^9

d: 3^500=243^100

7^300=343^100

=>3^500<7^300