Let A represent the speed of car A. Using your formula,
.. A*2 = D
.. (A +15)*1.5 = D . . . . . the same distance in a shorter time at a higher speed
Equating the two expressions for D, we get
.. 2A = 1.5(A +15)
.. 2A = 1.5A +22.5 . . . . . eliminate parentheses
.. 0.5A = 22.5 . . . . . . . . .subtract 1.5A
.. A = 22.5/0.5 = 45 . . . .divide by 0.5
Car B was 15 mph faster than this.
Car B traveled at 60 miles per hour.
Answer:
90 + 3 - 180 = 87
Step-by-step explanation:
I remembered doing a problem like this in Algebra, but i think this is right
I suppose a DJ wants to select 4 different songs, then there are: 12*11*10*9 = 11880 ways to choose them.
If the order of the songs he plays doesn't matter, there are: 
ways to choose them.
Answer:
Step-by-step explanation:
4x^2-8x-5=0
The discriminant is the number under the √. In this case it's 144
Answer:
141.3 cm³
Step-by-step explanation:
V=πr2h=π·32·5≈141.37167cm³
