Sara went to the park and saw that there were a total of 15 bicycles and tricycles. If the total number of wheels was 39, how many tricycles were there?

bi = 2 wheels
tri = 3 wheels

Please help me, I'm really struggling with this problem

can anyone help me please

To solve this problem, we can use a system of equations. Let's start by defining our variables:

Let's call the number of bicycles "b" and the number of tricycles "t".

We know that the total number of bicycles and tricycles is 15:

b + t = 15 ------ Equation 1

We also know that the total number of wheels is 39:

2b + 3t = 39 ------ Equation 2

Now, we have a system of two equations with two variables. We can solve this system to find the values of "b" and "t".

To eliminate one variable, we can multiply Equation 1 by 2. By doing this, both equations will have "b" with the same coefficient, so we can subtract them:

2b + 2t = 30 ------ Equation 3

2b + 3t = 39 ------ Equation 2

By subtracting Equation 3 from Equation 2, we can eliminate "b":

(2b + 3t) - (2b + 2t) = 39 - 30

t = 9

So, there are 9 tricycles.

To find the number of bicycles, we can substitute the value of t (9) into Equation 1:

b + 9 = 15

b = 6

Therefore, there are 6 bicycles.

In summary, there are 6 bicycles and 9 tricycles at the park.