Sarah bought pencils and markers for school. She bought 3 times as many pencils as markers. The pencils cost $0.15 each and the markers cost $0.30 each. In total, Sarah spent $7.50 on
pencils and markers. How many pencils did Sarah buy?
1. Define a variable for this problem. (For example: ' n = hours watching tv")
2. Create a model in words or in numbers that could solve this problem.
3. Solve the problem.

Sarah bought 30 pencils

Step-by-step explanation:

1. Let define p, as the number of pencils bought, and m, as the number of markers bought.

2.

3. Substitute p in the first equation to 3m since p=3m as defined.

plug m into equation p=3m to find the number of pencils bought

  y= -3x is the required function.

step-by-step explanation:

we have been given a table:

x             y

0             0

1             -3

3             -9

-2             6

we can see that the values of y is -3 times the value of x

hence, the function would be: y= -3x.

put the values of x will give the same y as in the table that means function is satisfying the given table.