Question

Simplify an find the value of each expressions when x equals 3
a) x⁵ - 3( x - 5 ) + 6x^​2

Answer 1

$$\begin{gathered} \mathrm{Consider}\mathrm{the}\mathrm{following}\mathrm{expression}. \\ {\mathrm{x}}^5-3\left(\mathrm{x}-5\right)+6{\mathrm{x}}^2 \\ \mathrm{Rearrange}\mathrm{the}\mathrm{terms}\mathrm{to}\mathrm{get}, \\ {\mathrm{x}}^5+6{\mathrm{x}}^2-3\left(\mathrm{x}-5\right) \\ \mathrm{Take}{\mathrm{x}}^2\mathrm{as}\mathrm{common}\mathrm{from}\mathrm{first}\mathrm{two}\mathrm{terms}\mathrm{to}\mathrm{get}, \\ {\mathrm{x}}^2\left({\mathrm{x}}^3+6\right)-3\left(\mathrm{x}-5\right) \\ \mathrm{Take}\mathrm{x}=3\mathrm{to}\mathrm{get}, \\ {\mathrm{x}}^2\left({\mathrm{x}}^3+6\right)-3\left(\mathrm{x}-5\right)={\left(3\right)}^2\left({\left(3\right)}^3+6\right)-3\left(3-5\right) \\ =9\left(27+6\right)-3\left(3-5\right) \\ =9\left(33\right)-3\left(-2\right) \\ =297+6 \\ =\mathbf{303} \end{gathered}$$