A bag contains blue marbles and red marbles, 48 in total. The number of blue marbles is 9 more than 2 times the number of red marbles. How many blue marbles are there?

35 Blue Marbles.

Step-by-step explanation:

This is a complex problem, since the value of 2R has to be divided by 2 beforing adding the value of B, to get the total of 48.

B=35 R=13

B=9+2R.

48=9 + (2R:2) 48=9 + (2 (13) : 2)

48=9+26+13 48=35+13

48=48.

There are 35 blue marbles

Step-by-step explanation:

b = blue marbles

r = red marbles

r+b = 48

b = 2r+9

Substitute b = 2r+9 into the first equation

r + (2r+9) = 48

Combine like terms

3r + 9 = 48

Subtract 9 from each side

3r+9-9 = 48-9

3r = 39

Divide each side by 3

3r/3 = 39/3

r = 13

There are 13 red marbles

We need to find the blue marbles

b = 2r+9

b = 2 (13) + 9

= 26+9

= 35

There are 35 blue marbles