\(\frac{x+3}{x-9}+\frac{2}{\sqrt{x}+3}-\frac{1}{3-\sqrt{x}}\)=\(\frac{x-3}{\left(\sqrt{x}\right)^2-3^2}+\frac{2}{\sqrt{x}+3}+\frac{1}{\sqrt{x}-3}\)=\(\frac{x+3}{\left(\sqrt{x}+3\right)\left(\sqrt{x}-3\right)}+\frac{2}{\sqrt{x}+3}+\frac{1}{\sqrt{x}-3}\)= \(\frac{x+3+2\left(\sqrt{x}-3\right)+1\left(\sqrt{x}+3\right)}{\left(\sqrt{x}+3\right)\left(\sqrt{x}-3\right)}\)

= \(\frac{x+3+2\sqrt{x}-6+\sqrt{x}+3}{\left(\sqrt{x}+3\right)\left(\sqrt{x}-3\right)}\)= \(\frac{\left(\sqrt{x}\right)^2-3\sqrt{x}}{\left(\sqrt{x}+3\right)\left(\sqrt{x}-3\right)}\)= \(\frac{\sqrt{x}\left(\sqrt{x}-3\right)}{\left(\sqrt{x}+3\right)\left(\sqrt{x}-3\right)}\)

= \(\frac{\sqrt{x}}{\sqrt{x}+3}\)

Hình như đề này thiếu hay sao ấy

20 + 20 = 40 

Nhớ tích nha !!!!   thanks 

bang 40

nha

ban

saturn

Chuẩn rồi chj gái ạ!

Hok tốt nha!

#miu

chuẩn rồi chj gái ạ! 

Nhớ k e nhé!

#miu

thời gian xe đi từ a đi là: 5-4=1 giờ

quãng đường xe đó đi là: 1x6=6 km

...

mk nghĩ đề này sai roy, mong bn xem lại nha =.="

~Hy

(2x+3)\(^2\) = \(\frac{25}{9}\)

=> 2x+3 = \(\frac{5}{3}\)

=> 2x = \(\frac{5}{3}\) - 3

=> 2x = \(-\frac{4}{3}\)

=> x =\(-\frac{2}{3}\)

TH2: (2x+3)\(^2\) =\(\frac{29}{5}\)

=> 2x+3 = \(-\frac{5}{3}\)

=> 2x = \(-\frac{5}{3}\) - 3

=> 2x = \(-\frac{14}{3}\)

=> x = \(-\frac{7}{3}\)

a)\(\frac{-17}{30}-\frac{11}{-15}+\frac{-7}{12}=\frac{-17}{30}-\frac{22}{-30}+\frac{-7}{12}\)

= \(\frac{-39}{30}+\frac{-7}{12}=\frac{-78}{60}+\frac{-35}{60}\)

= \(\frac{-113}{60}\)

b)\(\frac{-5}{9}+\frac{5}{9}:\left(1\frac{2}{3}-2\frac{1}{12}\right)\)

=\(\frac{-5}{9}+\frac{5}{9}:\left(\frac{5}{3}-\frac{25}{12}\right)\)

= \(\frac{-5}{9}+\frac{5}{9}:\left(\frac{20}{12}-\frac{25}{12}\right)\)

= \(\frac{-5}{9}+\frac{5}{9}:\frac{-5}{12}=\frac{-5}{9}+\frac{4}{-3}\)

=\(\frac{-5}{9}+\frac{12}{-9}=\frac{-5}{9}+\frac{-12}{9}=\frac{-17}{9}\)

chúc bn học tốt !