ai giúp với ạ :<
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
a: 12h: 0 độ
10h: 60 đọ
6h: 180 độ
5h: 150 độ
b:
a: góc nhọn: góc yMz; góc tMz
b: góc vuông: góc yMt, góc xMt
c: góc tù: góc xMz
d: góc bẹt: góc xMy
![](https://rs.olm.vn/images/avt/0.png?1311)
\(a,
\dfrac{-3}{7}-\left(\dfrac{5}{9}-\dfrac{3}{7}\right)
\)
\(=\dfrac{-3}{7}-\dfrac{5}{9}+\dfrac{3}{7}\)
\(=\dfrac{-3}{7}+\dfrac{3}{7}-\dfrac{5}{9}\)
\(=0-\dfrac{5}{9}\)
\(=\dfrac{-5}{9}\)
`a)`
`-3/7-(5/9-3/7)`
`=-3/7-5/9+3/7`
`=(-3/7+3/7)+(-5/9)`
`=0+(-5/9)=-5/9`
`b)`
`=5/7(2/11+3/11-1(5)/11)`
`=5/(7).(-1)`
`=-5/7`
`@Shả`
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
Bài 1:
\(a,\Leftrightarrow m-1\ne0\Leftrightarrow m\ne1\\ b,\Leftrightarrow m-1>0\Leftrightarrow m>1\\ c,\Leftrightarrow m-1< 0\Leftrightarrow m< 1\)
Bài 2:
\(a,\text{Đồng biến}\Leftrightarrow2m>0\Leftrightarrow m>0\\ \text{Nghịch biến}\Leftrightarrow m-1< 0\Leftrightarrow m< 1\\ b,\Leftrightarrow\left\{{}\begin{matrix}2m=m-1\\m+1\ne3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}m=-1\\m\ne2\end{matrix}\right.\Leftrightarrow m=-1\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\left\{{}\begin{matrix}R1=\dfrac{U1^2}{P1}=\dfrac{110^2}{1000}=12,1\Omega\\R2=\dfrac{U2^2}{P2}=\dfrac{110^2}{1500}=\dfrac{121}{15}\Omega\end{matrix}\right.\)
\(MCD:R1ntR2\)
\(->R=R1+R2=12,1+\dfrac{121}{15}=\dfrac{121}{6}\Omega\)
\(=>I=I1=I2=\dfrac{U}{R}=\dfrac{220}{\dfrac{121}{6}}=\dfrac{120}{11}A\)
\(=>\left\{{}\begin{matrix}P1=I1^2\cdot R1=\left(\dfrac{120}{11}\right)^2\cdot12,1=1440\\P2=I2^2\cdot R2=\left(\dfrac{120}{11}\right)^2\cdot\dfrac{121}{15}=960\end{matrix}\right.\)(W)