She buys 24 dvds in 12 weeks.
Answer:
Chips = 14
Pretzel = 14
Cookie = 8
Popcorn = 13
Question Mark = 222
Step-by-step explanation:
First Equation:
Chips + Pretzel + Chips = 42
Third Equation: Chips = Pretzel.
This means that
Pretzel + Pretzel + Pretzel = 42
Pretzel = 
Chips = Pretzel
Chips = 
Second Equation:
Cookie + Chips + Cookie = 30
We know that Chips = 14.
Cookie + 14 + Cookie = 30
Subtract 14 on both sides:
Cookie + Cookie = 16
Cookie =
.
Fourth Equation:
Cookie + Cookie + Popcorn = 29
We know that Cookie = 8.
8 + 8 + Popcorn = 29
16 + Popcorn = 29
Subtract 16 on both sides:
Popcorn = 13.
Question Mark:
(Popcorn + Popcorn)
Cookie + Chips = (13 + 13)
8 + 14 = 26
8 + 14 = 
Using the formula for the area of a triangle we can solve for the base.
The formula for area of a triangle is : Area = 1/2 x base x height
We are given the area and the height:
33.6 = 1/2 x 4 x base
Multiply both sides by 2 to remove the 1/2:
67.2 = 4 x base
Divide both sides by 4 to solve for the base:
67.2 /4 = 16.8
Check: Area = 1/2 x 4 x 16.8 = 33.6
The base is 16.8 inches.
Zero slope line coinciding with x axis and undefined slope line coinciding with y axis
The fractions you're given can be simplified down, so you get (12 ÷ 3) 4 hours on Monday, (21 ÷ 3) 7 hours on Tuesday, and (22 ÷ 3) 7 1/3 hours on Wednesday. You can now add these up and get your answer as 18 1/3 hours, or 18.33.
I hope this helps!