a, \(\left(x+2\right)\left(x+3\right)-\left(x-2\right)\left(x+5\right)=0\)
\(\Rightarrow x^2+3x+2x+6-\left(x^2+5x-2x-10\right)=0\)
\(\Rightarrow x^2+5x+6-x^2-3x+10=0\)
\(\Rightarrow2x=-10-6=-16\)
\(\Rightarrow x=-8\)
b, \(\left(2x+3\right)\left(x-4\right)+\left(x-5\right)\left(x-2\right)=\left(3x-5\right)\left(x-4\right)\)
\(\Rightarrow2x^2-8x+3x-12+x^2-2x-5x+10=3x^2-12x-5x+20\)
\(\Rightarrow2x^2+x^2-3x^2-8x+3x-2x-5x+5x+12x=20+12-10\)
\(\Rightarrow5x=22\Rightarrow x=\dfrac{22}{5}\)
Chúc bạn học tốt!!!
\(\left(x+2\right)\left(x+3\right)-\left(x-2\right)\left(x+5\right)=0\)
\(\Rightarrow x\left(x+3\right)+2\left(x+3\right)-x\left(x+5\right)+2\left(x+5\right)=0\)
\(\Rightarrow x^2+3x+2x+6-x^2+5x+2x+10=0\)
\(\Rightarrow\left(x^2-x^2\right)+\left(3x+2x+5x+2x\right)+\left(10+6\right)=0\)
\(\Rightarrow12x+16=0\)
\(\Rightarrow12x=16\Rightarrow x=\dfrac{4}{3}\)
