20. eat

21. is playing

22. washes

23. rings

24. bring

eat

is playing

washes

rings

bring

Chúc em học tốt

20 eat

21 is playing

22 washes

23 rings

24 bring

4:

a: =>2/5x+7/20-2/20=1/10

=>2/5x+5/20=1/10

=>2/5x=1/10-1/4=4/40-10/40=-6/40=-3/20

=>x=-3/20:2/5=-3/20*5/2=-15/40=-3/8

b: 3/2-1/2x=-1/3+3=8/3

=>1/2x=3/2-8/3=9/6-16/6=-7/6

=>x=-7/6*2=-7/3

c: 15/8-1/8:(1/4x-0,5)=5/4

=>1/8:(1/4x-1/2)=15/8-5/4=15/8-10/8=5/8

=>1/4x-1/2=1/8:5/8=1/5

=>1/4x=1/5+1/2=7/10

=>x=7/10*4=28/10=2,8

d: \(\Leftrightarrow\left[\left(x+\dfrac{1}{2}\right)^3-\dfrac{5}{4}\right]=\dfrac{11}{4}-\dfrac{5}{8}=\dfrac{22-5}{8}=\dfrac{17}{8}\)

=>\(\left(x+\dfrac{1}{2}\right)^3=\dfrac{17}{8}+\dfrac{5}{4}=\dfrac{27}{8}\)

=>x+1/2=3/2

=>x=1

11)

\(\dfrac{2x}{x+2}\) \(\times\) \(\dfrac{x^{2^{ }}-4}{4}\) - \(\dfrac{x}{2}\) 

= \(\dfrac{2x}{x+2}\) \(\times\) \(\dfrac{x^2-2^2}{4}\) - \(\dfrac{x}{2}\) 

= \(\dfrac{2x}{x+2}\) \(\times\) \(\dfrac{\left(x-2\right)\left(x+2\right)}{4}\) - \(\dfrac{x}{2}\) 

= \(\dfrac{x\left(x-3\right)}{2}\)

A nhé

a: Xét ΔABC có BM/BC=BD/BA

nên MD//AC

=>MM' vuông góc AB

=>M đối xứngM' qua AB

b: Xét tứ giác AMBM' có

D là trung điểm chung của AB và MM'

MA=MB

Do đó: AMBM' là hình thoi

a: ĐKXĐ: x<>2; x<>-3

b: \(P+\dfrac{x^2-4-5-x-3}{\left(x-2\right)\left(x+3\right)}=\dfrac{\left(x-4\right)\left(x+3\right)}{\left(x-2\right)\left(x+3\right)}=\dfrac{x-4}{x-2}\)

c: Để P=-3/4 thì x-4/x-2=-3/4

=>4x-8=-3x+6

=>7x=14

=>x=2(loại)

e: x^2-9=0

=>x=3 (nhận) hoặc x=-3(loại)

Khi x=3 thì \(P=\dfrac{3-4}{3-2}=-1\)