Answer:
Formulas
Step-by-step explanation:
Formulas are all unique and share the common trait of "x" and "y" values and a common purpose of helping you find the x and y value and/or answer to your question.
Answer:
12.63 km/hr
Step-by-step explanation:
Given the distance=240km
At 12 km/hr it will take =240/12 =20
time for Express train = 20-1=19
speed=240/19=12.63...km/hr
Answer:

Step-by-step explanation:
Use distributive property: 
What is -x * x^2? Answer: -x^3
What is 3 * x^2? Answer: +3x^2
What is -x * -4x? Answer: +4x^2
What is 3* -4x? Answer: -12x
What is -x * -6? Answer: +6x
What is 3 * -6? Answer: -18

Combine like terms, and your answer would be....

Hope this helps :)
Have a great day!