a,A=(100-2)(100+2)=100²-4<B

b,A=(200-5)(200+5)=200²-25<B

B=\(\left\{-1;1;7;25;29\right\}\)

a.A=2+2²+...+2¹⁰

2A-A=2¹⁰-1

B=5.2⁸=256.5=1280

A<B

a,=sin²a

b,=2

c,=sin³a

d,=1

viếng gì

\(\dfrac{2}{3}=\dfrac{2.6}{3.6}=\dfrac{12}{18}\)

\(\dfrac{5}{6}=\dfrac{5.3}{6.3}=\dfrac{15}{18}\)

\(\dfrac{7}{9}=\dfrac{7.2}{9.2}=\dfrac{14}{18}\)

\(1=\dfrac{1.18}{1.18}=\dfrac{18}{18}\)

các phân số này có cùng mẫu số nên ta chỉ cần so sánh tử số

Mà:12<14<15<18

Vậy:\(1\),\(\dfrac{5}{6}\),\(\dfrac{7}{9},\dfrac{2}{3}\)

a,B=\(\left(\dfrac{3}{4}-3\right):2=\dfrac{-9}{4}:2=-\dfrac{9}{8}\)

b,\(M=A.B\)

=\(\dfrac{\sqrt{x}+3+\sqrt{x}+11}{x-9}.\dfrac{\sqrt{x}-3}{2}\)=\(\dfrac{2\sqrt{x}+14}{\sqrt{x}+3}.\dfrac{1}{2}=\dfrac{\sqrt{x}+7}{\sqrt{x}+3}\)

D=\(\dfrac{cot71}{cot71}-\dfrac{1}{2}-1=-\dfrac{1}{2}\)

\(\dfrac{5}{12}=\dfrac{5.3}{12.3}=\dfrac{15}{36}\)

\(\dfrac{7}{18}=\dfrac{7.2}{18.2}=\dfrac{14}{36}\)

. là dấu nhân nha

\(11^4:121=11^2\)

C.11²