Question

$$2. P ( x ) = 2 x ^ { 4 } - 13 x ^ { 3 } + 30 x ^ { 2 } - 28 x + 8$$

Answer

$$P=((2*x-1)*(x-2)^3)/(2*x)$$

Solution


Divide both sides by \(2\).
\[Px=\frac{2{x}^{4}-13{x}^{3}+30{x}^{2}-28x+8}{2}\]
Divide both sides by \(x\).
\[P=\frac{\frac{2{x}^{4}-13{x}^{3}+30{x}^{2}-28x+8}{2}}{x}\]
Simplify  \(\frac{\frac{2{x}^{4}-13{x}^{3}+30{x}^{2}-28x+8}{2}}{x}\)  to  \(\frac{2{x}^{4}-13{x}^{3}+30{x}^{2}-28x+8}{2x}\).
\[P=\frac{2{x}^{4}-13{x}^{3}+30{x}^{2}-28x+8}{2x}\]
Factor \(2{x}^{4}-13{x}^{3}+30{x}^{2}-28x+8\) using Polynomial Division.
\[2x^3\]\[-9x^2\]\[12x\]\[-4\]
\[x-2\]\[2x^4\]\[-13x^3\]\[30x^2\]\[-28x\]\[8\]
\[2x^4\]\[-4x^3\]
\[-9x^3\]\[30x^2\]\[-28x\]\[8\]
\[-9x^3\]\[18x^2\]
\[12x^2\]\[-28x\]\[8\]
\[12x^2\]\[-24x\]
\[-4x\]\[8\]
\[-4x\]\[8\]
\[\]
Rewrite the expression using the above.
\[2{x}^{3}-9{x}^{2}+12x-4\]
\[P=\frac{(2{x}^{3}-9{x}^{2}+12x-4)(x-2)}{2x}\]
Factor \(2{x}^{3}-9{x}^{2}+12x-4\) using Polynomial Division.
\[P=\frac{(2{x}^{2}-5x+2)(x-2)(x-2)}{2x}\]
Split the second term in \(2{x}^{2}-5x+2\) into two terms.
\[P=\frac{(2{x}^{2}-x-4x+2)(x-2)(x-2)}{2x}\]
Factor out common terms in the first two terms, then in the last two terms.
\[P=\frac{(x(2x-1)-2(2x-1))(x-2)(x-2)}{2x}\]
Factor out the common term \(2x-1\).
\[P=\frac{(2x-1)(x-2)(x-2)(x-2)}{2x}\]
Use Product Rule: \({x}^{a}{x}^{b}={x}^{a+b}\).
\[P=\frac{(2x-1){(x-2)}^{3}}{2x}\]