Question

Answer 1

\(\Leftrightarrow-4x-3+5x+2=0\\ \Leftrightarrow x-1=0\Leftrightarrow x=1\)

Answer 2

\(\left(4x^4+3x^3\right):\left(-x\right)^3+\left(15x^2+6x\right):3x=0\\ \Rightarrow\left(-x^3\right)\left(-4x-3\right):\left(-x\right)^3+3x\left(5x+2\right):3x=0\\ \Rightarrow\left(-4x-3\right)+\left(5x+2\right)=0\\ \Rightarrow-4x-3+5x+2=0\\ \Rightarrow x-1=0\\ \Rightarrow x=1\)