The group rent 11 river rent tubes and 4 cooler tubes.
Step-by-step explanation:
Rent for river rent tube = $20
Rent for cooler tubes = $12.50
Total spent = $270
Total tubes rented = 15
Let,
x be the number of river rent tube.
y be the number of cooler tubes.
According to given statement;
x+y=15 Eqn 1
20x+12.50y=270 Eqn 2
Multiplying Eqn 1 by 20

Subtracting Eqn 2 from Eqn 3

Dividing both sides by 7.5

Putting y=4 in Eqn 1

The group rent 11 river rent tubes and 4 cooler tubes.
Keywords: linear equations, subtraction
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I believe the shorter sides are 5 feet and the longer ones are 10. This is because when you add up the two shorter sides as 10, and the other two as 20, then add them up to 30. That's the perimeter. For the area, you would do 10•5 to get 50 for the area
I hope this helps you
90-8.5
90-40
50
Sin 30 = O/H = 1/2
So Sin 30 = 1/2