1. Có sẵn kết quả kìa:))

2.\(B=\dfrac{2x-1}{x+1}-\dfrac{x+1}{x-1}-\dfrac{6}{\left(x-1\right)\left(x+1\right)}\)

\(B=\dfrac{\left(2x-1\right)\left(x-1\right)-\left(x+1\right)\left(x+1\right)-6}{\left(x-1\right)\left(x+1\right)}\)

\(B=\dfrac{2x^2-2x-x+1-x^2-2x-1-6}{\left(x-1\right)\left(x+1\right)}\)

\(B=\dfrac{x^2-5x-6}{\left(x-1\right)\left(x+1\right)}\)

\(B=\dfrac{\left(x-6\right)\left(x+1\right)}{\left(x-1\right)\left(x+1\right)}\)

\(B=\dfrac{x-6}{x-1}\left(đpcm\right)\)

Câu 1: A

Câu 2:B

Câu 3; C
Câu 15:B

Câu 9: D

Câu 10: A

B

C

C

D

D

C

D

C

A

A

1 B
2C
3A
4B
5A
7D
8A
9A
10C

Câu 2.

Nhiệt lượng bếp tỏa ra trong thời gian \(t=3min=180s\) là:

\(Q=UIt=RI^2t=60\cdot2,5^2\cdot180=675000J\)

Câu 3.

\(I_{Đ1}=\dfrac{U_{Đ1}}{R_{Đ1}}=\dfrac{6}{6}=1A\)

\(I_{Đ2}=\dfrac{U_{Đ2}}{R_{Đ2}}=\dfrac{1,5}{8}=\dfrac{3}{16}A\)

\(I_b=I_{Đ1}-I_{Đ2}=1-\dfrac{3}{16}=\dfrac{13}{16}A\)

\(R_b=\dfrac{U_b}{I_b}=\dfrac{1,5}{\dfrac{13}{16}}=\dfrac{24}{13}\Omega\)

Bài đây ạ

đề đâu vậy

đề đâu bn