<h3>
Answer:</h3>

<h3>
Explanation:</h3>
Change
so that is has a common denominator. 
Make an equation. 
Add. 
Add. 
Divide both sides by 2. 
Convert to a mixed number. 
I’m pretty sure it’s the third one sorry if i’m wrong
800+16x=720+21x
80+16x=21x
80=5x
X=16
So 16 hours :)
Answer:
Step-by-step explanation:
The volume of the pyramid = (1/3)*area of base *height
= (1/3)*10*24*13 = 1040 cubic units.
The total surface area = area of rectangular base + area of 2 isosceles triangles with a base of 24 units + area of 2 isosceles triangles with a base of 10 units.
Area of rectangular base = 24*10 = 240 sq units.
The slant height of isosceles triangles with a base of 24 units = [(10/2)^2+13^2]^0.5 = [25+169]^0.5 = 194^0.5 = 13.92838828 units.
The area of 2 isosceles triangles with a base of 24 units 2*24*13.92838828/2 = 334.2813187 sq units.
The slant height of isosceles triangles with a base of 10 units = [(24/2)^2+13^2]^0.5 = [144+169]^0.5 = 194^0.5 = 17.69180601 units.
The area of 2 isosceles triangles with a base of 10 units 2*10*17.69180601/2 = 176.9180601 sq units.
The total surface area of the pyramid = 240 + 334.2813187 + 176.9180601 = 591.9731247 sq units.
Maybe offer to make a deal with them where if you get all A's in your normal classes you can quit. It really depends on why you're taking the class in the first place. If it's not affecting your grades in any way, maybe it's best to just stay for the benefits of it.