If you have 8 yellow balloons for every 12 blue balloons, then if you have 20 balloons in total, 8 out of 20 of those balloons will be yellow. Then you can set up this ratio.
Then, you can use either cross multiplication or multiply the numerator and denominator by the same number to help solve for x. Personally, I prefer cross multiplication.
Finally, solve for x and if you had 100 balloons, you will have 40 yellow balloons.
Example A means
For every #of felt pieces you multiply that by the cost of one piece of felt to see how much you spent
Example
Felts cost $3 a piece
You get 7 pieces
7 x 3= 21
You spent $21 on felt
Answer:
(a+b,c)
Step-by-step explanation:
Note that the midpoint formula is:

Point A (0,0) and Point C (2a+2b,2c)
It follows that:

Answer:
40
Step-by-step explanation:
210-x=50×2
or, 210-x=100
or, x=210-100
or, x=110
so,
z = 360-210-110
or, z = 40
Answer:
Each friend gets
of the popcorns.
Step-by-step explanation:
Nathalie's brother takes 1/5 of the popcorn for himself.
so there is ( 1 - 1/5)
= 4/5 of the popcorns left in the bowl
including Nathalie and her 3 friends, there are (3 + 1) = 4 persons.
So, each friend gets

=
of the popcorns