Answer:
13x² - 4x
Step-by-step explanation:
3x + 4x² - 7x + 9x² ← collect like terms
= (4x² + 9x² ) + (3x - 7x)
= 13x² + (- 4x)
= 13x² - 4x
Answer:
72 km/hour
Step-by-step explanation:
20 m/s × (1 km/(1000 m)) × (3600 s/h) = 72 km/h
The rate is 72 kilometers per hour.
It is decreasing, since the y-value is going down.
