Answer:
There are 8 black marbles.
Step-by-step explanation:
First, set up your equation. You have black (b) and white (w) marbles, total of 30, so those will be your variables to set in your equation.
w + b = 30
You mentioned that there are 14 more white marbles then black. Therefore, white marbles will have b many marbles + 14, creating the equation:
w= b + 14
If w = b + 14 and w can be easily substituted in the first equation, substitute w for b + 14. This will result in having the equation of:
(b +14) + b= 30
Simplify this equation, combine like terms to break down the equation, making it easier for you to solve for b.
-Subtract 14 from both sides.
-Add b + b = 2b
Then, you will have your resulting equation in which you divided 2 from both sides to get b by itself.
2b = 16
b=8
There are 8 black marbles.