In Cleo’s class, the number of girls is 3 times the number of boys. There are a total of 28 students in the class. How many boys and girls are in Cleo’s class? Let x = girls and y = boys. Solve the system and write your answer in the form (x, y), using no spaces. If your answer is a fraction, write your answer in decimal form.

x + y = 28 and 3x + x = 28

Explanation: x + y = 28 is a pretty straightforward equation stating that the sum of x (number of boys) + the sum of y (number of girls) = 28 total students

3x + x = 28, because the amount of girls is three times the number of boys, I wrote the number of boys (x) multiplied by 3 to represent the population of girls and added an additional x to represent the number of boys

Upon further simplification you will get 4x = 28, which can be divided by 4 on both sides to solve for x, or the number of boys. 28/4 = 7, therefore x = 7.

Next, you plug x back into the original equation to get 7 + y = 28. For the final step, subtract 7 from both sides of the equation which will give you y = 21

The class has 7 boys and 21 girls, for a total population of 28 students.