Question

\(\left(x-5\right)\left(-x+4\right)-\left(x-1\right)\left(x+3\right)=-2x^2\)
tìm x ạ cứu e

Answer 1

\(\Leftrightarrow-x^2+4x+5x-20-x^2-2x+3=-2x^2\)

=>7x-17=0

hay x=17/7

Answer 2

\(\left(x-5\right)\left(-x+4\right)-\left(x-1\right)\left(x+3\right)=-2x^2\)

\(\Rightarrow-x^2+4x+5x-20-x^2-3x+x+3=-2x^2\)

\(\Rightarrow-2x^2+11x-17=-2x^2\)

\(\Rightarrow11x-17=0\)

\(\Rightarrow x=\dfrac{17}{11}\)