Question

Tìm x biết:

2.(x+5)-x^2-5x=0

Answer 1

\(2.\left(x+5\right)-x^2-5x=0\)

\(2.\left(x+5\right)-\left(x^2+5x\right)=0\)

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

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

=> \(\orbr{\begin{cases}x+5=0\\2-x=0\end{cases}}\)=> \(\orbr{\begin{cases}x=-5\\x=2\end{cases}}\)

Answer 2

2(x+5)-x²-5x=0

2(x+5)-(x²+5x)=0

2(x+5)-x(x+5)=0

(2-x)(x+5)=0

2-x=0 hoặc x+5=0

x=2 hoặc x=-5

Answer 3

2(x+5)-x^2-5x=2(x+5)-x(x+5)=0

<=>(2-x)(x+5)=0

<=>2-x=0<=>x=2

      x+5=0<=>x=-5