= \(\frac{4}{3}\)+ \(\frac{6}{5}\)x y - \(\frac{4}{5}\)= \(\frac{14}{5}\)

= \(\frac{8}{15}\)+ \(\frac{6}{5}\)x y = \(\frac{14}{5}\)

\(\frac{6}{5}\)x y = \(\frac{14}{5}\)- \(\frac{8}{15}\)= \(\frac{6}{15}\)

y = \(\frac{6}{15}\): \(\frac{6}{5}\)

y = \(\frac{1}{3}\)

a) 2/3 + 5/2 - 3/4

= 19/6 - 3/4

= 29/12

b) 2/5 x 1/2 : 1/3

= 1/5 x 3

= 3/5 

2/9 : 2/9 x 1/2

= 1 x 1/2 

= 1/2

\(\frac{3}{4}\)x 8,4 + 2,8 x \(1\frac{1}{2}\)

= 0,75 x 8,4 + 2,8 x \(\frac{3}{2}\)

= 0,75 x 8,4 + 2,8 x 1,5

= 6,3 + 4,2

= 10,5

\(\frac{3}{4}\times8,4+2,8\times1\frac{1}{2}\)

\(=6,3+4,2\)

\(=10,5\)

Kết bạn với mình nha!

cam on cac cau nha 

thanks you very much

đề gi rõ ra mới tính được

\(\frac{2}{3}\cdot x:\frac{1}{5}=1\frac{1}{3}:\frac{1}{4}\)

\(\Leftrightarrow\frac{2}{3}\cdot x:\frac{1}{5}=\frac{16}{3}\)

\(\Rightarrow\frac{2}{3}\cdot x=\frac{16}{3}\cdot\frac{1}{5}\)

\(\Rightarrow x=\frac{16}{15}:\frac{2}{3}\)

\(\Rightarrow x=\frac{8}{5}\)

Ta có :

\(\frac{2}{3}x:\frac{1}{5}=1\frac{1}{3}:\frac{1}{4}\)

\(\frac{2}{3}x:\frac{1}{5}=\frac{1}{3}:\frac{1}{4}\)

\(2x:\frac{1}{5}=\frac{4}{3}\)

\(2x=\frac{4}{3}.\frac{1}{5}\)

\(2x=\frac{4}{15}\)

\(x=\frac{4}{15}:2\)

\(\Rightarrow x=\frac{2}{15}\)

\(x^2-6x+9=\left(x-3\right)^2\)

\(4x^2+4x+1=\left(2x+1\right)^2\)

\(x^3+6x^2+12x+8=x^3+3.x^2.2+3.x.2^2+2^3=\left(x+2\right)^3\)

\(27x^3-27x^2+9x-1=\left(3x-1\right)^3\)( sửa đề chút )

\(\left(3x+2\right)\left(9x^2-6x+4\right)=\left(3x\right)^3+2^3\)( sửa đề chút )

Tham khảo nhé~