Xét ΔOHA vuông tại H và ΔOKA vuông tại K có

OA chung

OH=OK

Do đó: ΔOHA=ΔOKA

Suy ra: AH=AK

hay AB=AC

bài này thầy mới ra nè, trùng hợp qá

s nhìn hình khó thế nhở????

Rtđ=((R5+R6)*(((R1*R2)/(R1+R2))+((R3*R4)/(R3+R4)))/((R5+R6)+((R1*R2)/(R1+R2))+((R3*R4)/(R3+R4)))

Iab=U/Rtđ=110/Rtđ

U5=U6=(U1+U3)=(U2+U4)

U1=U2;U3=U4

((R1ntR2)//(R3ntR4))//(R5ntR6)

dựa theo mà làm

ta có:

[(R₁\\R₂) nt (R₃\\R₄)]\\(R₅ nt R₆)

R₁₂=\(\frac{R_1\cdot R_2}{R_1+R_2}\)=142,85\(\Omega\)

R₃₄=\(\frac{R_3\cdot R_4}{R_3+R_4}=222,2\Omega\)

R₁₂₃₄=R₁₂+R₃₄=365\(\Omega\)

R₅₆=R₅+R₆=900\(\Omega\)

R=\(\frac{R_{1234}\cdot R_{56}}{R_{1234}+R_{56}}=260\Omega\)

I=\(\frac{U}{R}=0.42A\)

mà U=U₁₂₃₄=110V

\(\Rightarrow I_{1234}=\frac{U_{1234}}{R_{1234}}\)=0.3A

mà I₁₂₃₄=I₁₂=I₃₄

\(\Rightarrow U_{34}=I_{34}\cdot R_{34}\)=66.6V

mà U₃₄=U₃=U₄

\(\Rightarrow I_3=\frac{U_3}{R_3}=0.1665A\)

Đề :

Tìm x thỏa mãn \(\frac{1+3y}{12}=\frac{1+6y}{16}=\frac{1+9y}{4x}\)

Bài làm :

Áp dụng tính chất của dãy tỉ số bằng nhau, có :

\(\frac{1+3y}{12}=\frac{1+6y}{16}=\frac{1+9y}{4x}=\frac{\left(1+3y\right)+\left(1+9y\right)}{12+4x}\)

\(=\frac{2+12y}{12+4x}\)

\(\Rightarrow\frac{1+6y}{16}=\frac{2+12y}{12+4x}=\frac{2\left(1+6y\right)}{2\left(6+2x\right)}=\frac{1+6y}{6+2x}\)

\(\Rightarrow6+2x=16\)

\(\Leftrightarrow2x=10\Rightarrow x=5\)

Vậy ...

ai giúp coi

I think it's gonna be like this:

5. I don't have much time so I don't use the Internet very often.

6. Tuan finds playing table tennis interesting because he often plays with his best friend.

7. I'm now having felt tired since I stayed up late to do my homework.

8. My homework will be finished by midnight.

9. We won't go anywhere until Tom comes.

10. That's one of the most interesting books I have ever read.

5 i don't have much time so i don't use the Internet very often.

6 Tuan finds playing table tennis interesting because he plays with his best friend

7 i have been feeling tired since i stayed up late to do my homework

8 My homework will have been finished be midnight

9 we haven't gone anywhere until Tom comes

10 that is one of the most interesting books i have ever read