a, để căn thức có nghĩa thì 3-5x≥0⇔x≤\(\dfrac{3}{5}\)

b, để căn thức có nghĩa thì 2x+1>0⇔x>\(\dfrac{-1}{2}\)

\(\sqrt{4}+\sqrt{15}-\sqrt{4}-\sqrt{15}-\sqrt{2}-\sqrt{3}\)

\(=-\sqrt{3}-\sqrt{2}\)

ỏ thanks

1.Hoa loves to play badminton so last weekend she went to play badminton with her dad.

2.I don't mind washing clothes so I did laundry last night.

3.My sister hates to watch action movies, but last night she watched an action movie.

4.Mai loves to play the piano, but last Saturday she didn't go to piano class.

nhầm xíu

ừa mị làm sai đó

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

3x²+3x-2x²-4x=1+x²

3x²+3x-2x²-4x-x²=1

x=-1

vậy............

số b là: 50:(5-3)=25

số a là: 25+50=75

vậy...

\(\dfrac{18}{54}=\dfrac{18:18}{54:18}=\dfrac{1}{3}\)