so cap so nguyen x,y thoar man dieu kien \(\frac{3}{x}+\frac{y}{3}=\frac{5}{6}\)

\(\frac{1}{a}+\frac{1}{b}=\frac{1}{a+b}\)Co bao mhieu cap so a,b?

Tam giac ABC,diem I thuoc AB sao cho \(\frac{AI}{AB}=\frac{1}{3}\),qua I ke cac duong thang song song BC,AC lan luot cat AC,BC tai D,E. Chi ra cac cap tam giac dong dang,viet cac cap goc bang nhau,cac ti so dong dang tuong ung

GIUP KHAN CAP

\(\frac{-2}{3}+\frac{9}{12}-\left(-\frac{1}{6}\right)-0,75\)

1) A={x∈R/|x-1|>1}

B=x∈R/\(\frac{1}{\left|x-2\right|}\)>1}

tìm A∪B,A∩B,A\B,B/A,CrA,CrB,CrA∩B.

Cho hình vuông ABCD,M∈CD,AM\(\cap\)BC={E}

đường thẳng vuông góc với AM={A}\(\cap\)CD={N}

OE=ON

C/m: a.B,D,O thẳng hàng

b.\(\frac{1}{AB^2}=\frac{1}{AM^2}+\frac{1}{AE^2}\)

c.OA⊥NE

d.\(\frac{1}{AD^2}\)≥\(\frac{2}{AM.AE}\)

Nhớ vẽ hình!!!!!!

tim cac cap so x,y biet:

\(\frac{x}{2}=\frac{y}{5}\)va x.y =90

\(\frac{3x-y}{x+y}=\frac{3}{4}\)tim\(\frac{x}{y}\)

\(A=\left[a;a+2\right];B=\left[0;2019\right];C=\left\{x\in R:\frac{|x|-1}{|x|}>0\right\}\)

Tìm a để A\(\cap\)B\(\cap\)C=\(\phi\)

Tim cap số nguyen x ; y sao cho \(\frac{x}{4}\)=\(\frac{2}{y}\)