Of the 50 students in the cafeteria, 7 have red hair. Suppose there are 750 students in the school. Write a proportion that could be used to predict the number of students who have red hair. Use x to represent the number of students who have red hair.

Given:

Of the 50 students in the cafeteria, 7 have red hair.

Total number of students = 750

To find:

The proportion that could be used to predict the number of students who have red hair.

Solution:

Let x represent the number of students who have red hair.

The ratio of student having red hair to the total number of students are

The number of students having red hair is proportional to the total number of students. So, the above ratios are equal.

Multiply both sides by 750.

Therefore, the required equation is and the number of students who have red hair is 105.

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations: