Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) Ta có BE là tia phân giác của góc B, nên góc EBA = góc EBC. Vì AB = BN, nên tam giác ABE và tam giác BNE là tam giác đồng dạng (cạnh AB tương ứng với cạnh BN). Do đó, ta có góc AEB = góc BEN.
\(b,\dfrac{2}{3}\left(2x+4\right)^2-\dfrac{1}{3}\left(x+1\right)^2=-\dfrac{1}{3}\left(2x+4\right)^2+\dfrac{2}{3}\left(x+1\right)^2\)
\(\Rightarrow\dfrac{2}{3}\left(2x+4\right)^2+\dfrac{1}{3}\left(2x+4\right)^2=\dfrac{2}{3}\left(x+1\right)^2+\dfrac{1}{3}\left(x+1\right)^2\)
\(\Rightarrow\left(2x+4\right)^2=\left(x+1\right)^2\)
\(\Rightarrow\left[{}\begin{matrix}2x+4=x+1\\2x+4=-\left(x+1\right)\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}2x-x=1-4\\2x+4=-x-1\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=-3\\2x+x=-1-4\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=-3\\3x=-5\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=-3\\x=-\dfrac{5}{3}\end{matrix}\right.\)
Vậy: \(x\in\left\{-3;-\dfrac{5}{3}\right\}\).
\(\left[\left(\dfrac{-3}{8}+\dfrac{11}{23}\right):\dfrac{5}{9}+\left(\dfrac{-5}{8}+\dfrac{12}{23}\right):\dfrac{5}{9}\right]\cdot\dfrac{11}{235}\)
\(=\left[\left(\dfrac{-3}{8}+\dfrac{11}{23}\right)\cdot\dfrac{9}{5}+\left(\dfrac{-5}{8}+\dfrac{12}{23}\right)\cdot\dfrac{9}{5}\right]\cdot\dfrac{11}{235}\)
\(=\dfrac{9}{5}\cdot\left(\dfrac{-3}{8}+\dfrac{11}{23}+\dfrac{-5}{8}+\dfrac{12}{23}\right)\cdot\dfrac{11}{235}\)
\(=\dfrac{9}{5}\cdot\left[\left(\dfrac{-3}{8}+\dfrac{-5}{8}\right)+\left(\dfrac{11}{23}+\dfrac{12}{23}\right)\right]\cdot\dfrac{11}{235}\)
\(=\dfrac{9}{5}\cdot\left(-1+1\right)\cdot\dfrac{11}{235}\)
\(=\dfrac{9}{5}\cdot0\cdot\dfrac{11}{235}\)
\(=0\)
In spite of loving ice-cream, Linda didn't eat more than one
One of my favorite hobby is playing football. I spend a lot of free time playing football after finishing my homework. I was so interested in playing football from my childhood and started learning to play when I was 9 years old. When I was 10 years old, my dad told my teacher about my hobby of football. My teacher told my dad that there was a facility for playing sports daily in school so he could admit his child. Now, I enjoy playing football and I participate in inter-school competitions.
a) 2/7 : x = 11/6 : 7/12
2/7 : x = 22/7
x = 2/7 : 22/7
x = 1/11
b) (2 - x)/3 = -3/(x - 2)
(2 - x)(x - 2) = -3.3
-(x - 2)² = -9
(x - 2)² = 9
x - 2 = 3 hoặc x - 2 = -3
*) x - 2 = 3
x = 3 + 2
x = 5
*) x - 2 = -3
x = -3 + 2
x = -1
Vậy x = -1; x = 5
c) (x - 1)/(x + 2) = 2/3
3(x - 1) = 2(x + 2)
3x - 3 = 2x + 4
3x - 2x = 4 + 3
x = 7
a) 2/7 : x = 11/6 : 7/12
2/7 : x = 22/7
x = 2/7 : 22/7
x = 1/11
b) (2 - x)/3 = -3/(x - 2)
(2 - x)(x - 2) = -3.3
-(x - 2)² = -9
(x - 2)² = 9
x - 2 = 3 hoặc x - 2 = -3
*) x - 2 = 3
x = 3 + 2
x = 5
*) x - 2 = -3
x = -3 + 2
x = -1
Vậy x = -1; x = 5
c) (x - 1)/(x + 2) = 2/3
3(x - 1) = 2(x + 2)
3x - 3 = 2x + 4
3x - 2x = 4 + 3
x = 7
Số lít dầu ăn dùng trong tuần lễ thứ hai là:
\(133,4+27,2=160,6\) ( lít )
Số lít dầu ăn trung bình của cả hai tuần lễ là:
\(\left(133,4+160,6\right):2=147\) ( lít )
Đ/s:...
thank you friend