Arace consists of three parts: a long run, biking, and a short run. the biking portion is 6 km longer than the long run and the short run is two-thirds the distance of the long run. the entire race is 56 km long. how long is the biking portion? answer should be to 2 decimal places.
only put the numerical answer and the units. ex. 5.87km

A sprint-distance triathlon is often the best way for a new triathlete to have positive experience in their first event. A typical sprint distance event consists of 400 to 500 yards (or meters) of swimming, 12 to 15 miles of cycling and typically a 3.1-mile run.  This distance makes completing the event quite manageable for fit and soon-to-be fit athletes.

- 2 + 10x³ - 21x² + 19x - 4

step-by-step explanation:

each term in the second factor is multiplied by each term in the first factor

x²(- 2x² + 4x - 1) - 3x(- 2x² + 4x - 1) + 4(- 2x² + 4x - 1) ← distribute

= - 2 + 4x³ - x² + 6x³ - 12x² + 3x -8x² + 16x - 4

collect like terms

= - 2 + 10x³ - 21x² + 19x - 4 ← in standard form