fish số nhiều giữ nguyên

cars

wives

highways

lines

noises 

pianos

fishes

farmers

men

ladies

Xét ΔABC có

\(\widehat{B}+\widehat{C}+\widehat{A}=180^0\)

\(\Leftrightarrow2\cdot\widehat{B}=180^0-\widehat{A}\)

hay \(\widehat{B}=\widehat{C}=\dfrac{180^0-\widehat{A}}{2}\)

Hông bé ơi 😊🤣🤣🤣🤣😅😂😂

a: =>x+2/3=4/60=1/15

=>x=1/15-2/3=1/15-10/15=-9/15=-3/5

b: =>x/3=14/21-3/21=11/21

=>x=11/7

\(x+\dfrac{2}{3}=-\dfrac{1}{12}.\dfrac{-4}{5}.\\ \Leftrightarrow x+\dfrac{2}{3}=\dfrac{1}{15}.\\ \Leftrightarrow x=\dfrac{-3}{5}.\\ \dfrac{x}{3}=\dfrac{2}{3}+\dfrac{-1}{7}.\\ \Leftrightarrow\dfrac{x}{3}=\dfrac{11}{21}.\\\Leftrightarrow \dfrac{7x}{21}=\dfrac{11}{21}.\\\Leftrightarrow7x=11.\\ \Leftrightarrow x=\dfrac{11}{7}. \)

14.8 và câu14.9 thôi nhé

Bài 2:

a: \(4xy^3-2=2\cdot2xy^3-2\cdot1=2\left(2xy^3-1\right)\)

b: \(5xy^3+2xy+4x^2y^2=xy\cdot5y^2+xy\cdot2+xy\cdot4xy\)

\(=xy\left(5y^2+2+4xy\right)\)

c: \(4x^2-3=\left(2x\right)^2-\left(\sqrt3\right)^2=\left(2x-\sqrt3\right)\left(2x+\sqrt3\right)\)

d: 5x(x-y)-2y(y-x)

=5x(x-y)+2y(x-y)

=(x-y)(5x+2y)

e: \(x^3-6x^2+12x-8\)

\(=x^3-3\cdot x^2\cdot2+3\cdot x\cdot2^2-2^3\)

\(=\left(x-2\right)^3\)

f: (x+1)(x+2)(x+3)(x+4)-3

\(=\left(x^2+5x+4\right)\left(x^2+5x+6\right)-3\)

\(=\left(x^2+5x+5\right)^2-1-3\)

\(=\left(x^2+5x+5\right)^2-4\)

\(=\left(x^2+5x+5+2\right)\left(x^2+5x+5-2\right)\)

\(=\left(x^2+5x+7\right)\left(x^2+5x+3\right)\)

h: \(6x^2-7x+1\)

\(=6x^2-6x-x+1\)

=6x(x-1)-(x-1)

=(x-1)(6x-1)