Question

Tìm x 

5x.(1-2x)-3x.(x+18)=0

Answer 1

5x(1 - 2x) - 3x(x + 18) = 0

=> 5x - 10x² - 3x² - 54x = 0

=> -13x² - 49x = 0

=> x.(-13x - 49) = 0

=> x = 0

hoặc -13x - 49 = 0 => -13x = 49 => x = -49/13

                                                                      Vậy x = 0, x = -49/13

Answer 2

\(5x\left(1-2x\right)-3x\left(x+18\right)=0\)

\(\Rightarrow x\left(5\left(1-2x\right)-3\left(x+18\right)\right)=0\)

\(\Rightarrow x\left(5-10x-3x+54\right)=0\)

\(\Rightarrow x\left(59-13x\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x=0\\59-13x=0\end{cases}\Rightarrow\orbr{\begin{cases}x=0\\13x=59\end{cases}\Rightarrow}\orbr{\begin{cases}x=0\\x=\frac{59}{13}\end{cases}}}\)

Answer 3

\(5x.\left(1-2x\right)-3x.\left(x+18\right)=0\)

=>\(5x-10x^2-3x^2-54x=0\)

=>\(-49x-13x^2=0\)

=>\(x\left(-49-13x\right)=0\)

=>x=0 hoặc -49-13x=0

Nếu -49-13x=0

=>13x=-49

=>x=\(\frac{-49}{13}\)

Vậy x=0 hoặc x=\(\frac{-49}{13}\)