Question

3.Express the product as a trinomial:(5x – 2)(3x+ 2)

Answer 1

To express the product of (5x - 2)(3x + 2) as a trinomial;

`\begin{gathered} (5x-2)(3x+2) \\ 15x^2+10x-6x-4 \\ \text{Note that the order of expanding the parenthesis is:} \\ \lbrack5x*3x\rbrack+\lbrack5x*2\rbrack-\lbrack2*3x\rbrack-\lbrack2*2\rbrack \\ 15x^2+4x-4 \\ \text{Multiply the product by x and you have} \\ x(15x^2+4x-4) \\ 15x^3+4x^2-4x \end{gathered}`

Note that a trinomial has its highest index power to the power of 3. Therefore to express the result as a trinomial (which already has its highest index power to the power of 2), you now multiply the result by x to the power of 1 (or simply x)