Answer: 56 purple marbles.
Step-by-step explanation:
Let be "p" the number of purple marbles in the bag and "w" the number of white marbles in the bag.
You can set up the following System of equations:
You can use the Substitution method to solve the System of equations. The steps are shown below:
1. You need to substitute the second equation into the first equation:
2. Now you must solve for "w":
3. Substitute the value of "w" into second original equation and then evaluate in order to find the value "p":
For this case we have the following situation:
The monthly cost of a gym in the city is $ 3. The initial registration is $ 25. Write a mathematical expression that models the problem.
So we have to define variables:
x: number of months
y: total cost
The mathematical expression that models the problem is: