Answer:
15 friends
Step-by-step explanation:
100-10 = 90 tubes available to share with friends.
90 ÷ 6 = 15
15 friends can pick 6 lip glosses each, leaving none left.
Answer:

Step By Step Explanation:
Follow PEMDAS Order Of Operations
Calculate Within Parenthesis: 

Calculate Exponents: 

Divide: 

Add

➤ 

Normal-travel DATA:
distance = 240 km
rate = x km/h
time = d/r
= 240/x hrs
_______________________
Bad weather DATA:
distance = 240 km
rate = (x-20) km/h
time = 240/(x-20) hrs
______________________
Bad time - normal time = 2 hrs
240/(x-20) - 240/x = 2
120/(x-20) - 120/x = 1
120x -120(x-20) = x(x-20)
20 = x^2 -20x
x^2 - 20x - 20 = 0
x = [20 +- sqrt(20^2 - 4*1*-20)]/2
x = [20 +- sqrt(480)]/2
x = [20 +- 4sqrt(30)]/2
x = 10 +- 2sqrt(30)
I think you would do this first add 3.50+1.75=5.25 ( amount she spent so far)
5.25+2x <= 24.50 solve the equation
first, subtract 5.25 from both sides then you get 2x=24.50 then x=12.25 so about 12 rides