5.9 > 0

5 . 9 >  0

a) 5.9 > 0

b) (-3) . (-47) > 15

c) (-3) .(-2) > (-3)

d) (-9) .(-7) > (9)

5.9 > 0

(-9).(-7). >.9

(-22).(-21)>420

(-21 ).(-5)..>... (-34).(-3)

(-3.(-47)..>.15

(-12).(-8)...>.90

(-18).(-21)..>..300

(-47).(-12)..<..(-27).(-22)

(-3).(-2).>..-3

(-15).(-28)..>..400

(-22).(-21)..>..320

(-17).(-3)...>...23.2

hok tốt!!!

\(A=\frac{1}{1.5}+\frac{1}{5.9}+...+\frac{1}{95.99}\)

\(A=\frac{1}{4}.\left(\frac{1}{1}-\frac{1}{5}+...+\frac{1}{95}-\frac{1}{99}\right)\)

\(A=\frac{1}{4}.\left(\frac{1}{1}-\frac{1}{99}\right)\)

\(A=\frac{1}{4}.\frac{98}{99}\)

\(A=\frac{49}{198}\)

Giờ ta so sánh : 

\(A=\frac{49}{198}\) và B=1 

Ta thấy :

\(\frac{49}{198}<1\)

=> A < B

Vậy A < B

\(A=\frac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.2^{10}}=\frac{2^{2.5}.3^{2.4}-2.2^9.3^9}{2^{10}.3^8+2^8.3^8.2^0}=\frac{2^{10}.3^8-2^{10}.3^9}{2^{10}.3^8+2^8.3^8}=\frac{2^{10}.3^8\left(1-3\right)}{2^8.3^8\left(2^2+1\right)}=\frac{4.-2}{5}=-\frac{8}{5}\)

ban kia lam dung roi do

k tui nha

thanks

\(72^{45}-72^{44}=72^{44}.\left(72-1\right)=72^{44}.71\)

\(72^{44}-72^{43}=72^{43}.\left(72-1\right)=72^{43}.71\)

Vì \(72^{44}>72^{43}\Rightarrow72^{45}-72^{44}>72^{44}-72^{43}\)