Answer:
7th graders- 100 students
8th graders- 110 students
Step-by-step explanation:
Let the number of 8th graders be represented by x and 7th graders be represented by y
<u>Equation based on number</u>
There difference between 8th and 7th graders is 10 hence equation becomes
x-y=10
<u>Equation based on contribution</u>
While x contribute each $8 and y contribute each $5, the total contribution is $1380 hence the equation becomes
8x+5y=1380
<u>Combining equations</u>
Having the two simultaneous equations which are
x-y=10
8x+5y=1380
Solving the equations.
5x-5y=50
8x+5y=1380
------------------
13x=1430
x=1430/13=110
Therefore, 8th graders are 110. Since the 8th graders were 10 more than 7th graders, the 7th graders will be 110-10=100 students
4. It's divided by 2 every time.
Set the sum of both expressions to 90 and then solve for x. this should give you x=6
