Answer:
About 630 seventh-grade students would like to snorkel
Step-by-step explanation:
if you do
7/9 x 90 equals 630/810 total students
M= 1/2x+6
N= 1/2x-3
They both have the same slope.
To get the answer, you need to think of it like a see-saw.
Both sides must equal the same relative to 33.5. For example, 32 is 1.5 away from 33.5 so you could say you have 1.5*4 (because theres 4 tubes with 32 sweets). If you were to do this for the whole table, it would look something like this:

This simplifies to:




This method can sometimes be inefficient depending on how many values but is probably the simplest way to solve this problem.
hope this helps :)
(sorry the other way is kinda hard to explain possibly ask your teacher tomorrow)
The formula to use is A=(b1+b2)h if one base is 24 and the other one is 16 which equals to 40 when you add then you still have H which is 12 so you could either divide 12 by two to get half or multiply by 12 and then divide it
40•12=480
480 divided by 2= 240
Your final answer should be 240ft
Get them to have a common denominator so you can add them
(1/3)×2= 2/6 and (1/2)×3= 3/6
Add them together
(2/6)+ (3/6)= 5/6
So 5/6 of the class planted either marigolds or tulips and 1/6 of the class planted neither