More than 18'students in an algebra class pass the first test. This is about three-fifths of the class. How many students are in the class? How do you know?

(3/5)x > 18

x > 18 / (3/5)

x > 18 * (5/3)

x > 30

To find out how many students are in the algebra class, we can use proportions.

We are given that more than 18 students pass the first test, which is about three-fifths of the class. Let's represent the total number of students in the class as "x".

Now, we know that the number of students who passed the test is more than 18. So, we can set up the following equation:

(3/5) * x > 18

To solve for x, we can multiply both sides of the inequality by 5/3 to cancel out the fraction:

x > (18) * (5/3)
x > 30

Therefore, the number of students in the algebra class must be greater than 30. However, we don't have an exact value for x.

To find out how many students are in the class, we can use a proportion.

Let's assume the total number of students in the class is "x".

According to the problem, more than 18 students passed the first test, which means it is greater than 18.

We also know that this number represents three-fifths of the class, which means:

(3/5) * x > 18

To solve this inequality, we can multiply both sides by 5 to get rid of the fraction:

3 * x > 18 * 5
3 * x > 90

Next, we divide both sides by 3 to isolate "x":

x > 90 / 3
x > 30

So, we know that the number of students in the class is greater than 30. However, we cannot determine the exact value unless we are given more information.