Answer:
43.9823
Step-by-step explanation:
We know there are a total of 36 marbles. We also know 24 out of 36 are black and 12 out of 36 are blue. A ratio is pretty much a division problem... The problem wants the 24 black marbles over the 12 blue marbles. So, 24/12 = 2/1. Now, what this means is that for every 2 black marbles, there is one 1 blue marble. Good luck!
Answer: 9+4n-1 = 20
We can solve this by substitution.
Replace n with the value given, 3 (remember 4n means 4 times n):
9 + 4*3 - 1
Then work it out using arithmetic
9+12-1
=20
