Question

Tìm x bt :

a,\(\left(x+2\right)\left(x+3\right)-\left(x-2\right)\left(x+5\right)=0\)

b, \(3x\left(x-5\right)-\left(x-1\right)\left(2+3x\right)\)

Answer 1

Câu a :

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

\(\Leftrightarrow x^2+3x+2x+6-x^2-5x+2x+10=0\)

\(\Leftrightarrow2x+16=0\)

\(\Rightarrow x=-8\)

Xem lại câu b .

Answer 2

Câu b chưa có ai làm!

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

\(\Rightarrow3x^2-15x-\left(2x+3x^2-2-3x\right)=0\)

\(\Rightarrow3x^2-15x+x-3x^2+2=0\)

\(\Rightarrow-14x=-2\Rightarrow x=\dfrac{1}{7}\)

Vậy..............................

Chúc bạn học tốt!!!