Question

$$F(x)=5 { x }^{ 3 } + { x }^{ 2 } -3x,g(x)= \frac{ 10 }{ 2 } { x }^{ 3-3x } + { x }^{ 2 }$$

Answer

x=0,-(1+sqrt(20*F+61))/10,-(1-sqrt(20*F+61))/10

Solution


Simplify  \(\frac{10}{2}\)  to  \(5\).
\[\begin{aligned}&Fx=5{x}^{3}+{x}^{2}-3x\\&gx=5{x}^{3-3x}+{x}^{2}\end{aligned}\]
Break down the problem into these 2 equations.
\[Fx=5{x}^{3}+{x}^{2}-3x\]
\[Fx=gx\]
Solve the 1st equation: \(Fx=5{x}^{3}+{x}^{2}-3x\).
\[x=0,-\frac{1+\sqrt{20F+61}}{10},-\frac{1-\sqrt{20F+61}}{10}\]
Solve the 2nd equation: \(Fx=gx\).
\[x=0\]
Collect all solutions.
\[x=0,-\frac{1+\sqrt{20F+61}}{10},-\frac{1-\sqrt{20F+61}}{10},0\]
Therefore,
\(x=0,-\frac{1+\sqrt{20F+61}}{10},-\frac{1-\sqrt{20F+61}}{10}\)