Start with
Add 2x to both sides:
Subtract 21 from both sides:
Divide both sides by 5. Since it is positive, we don't have to change the inequality sign:
So, the answer is 
Since it is a rectangular prism, the front and back are the same. the sides are the same and the top and bottom are the same. You would find the area of the front and back first. Since they both have the same measurements, you can find the area of one of the faces and multiply by 2.
A=BH
A= 3x5
A=15
15x2=30
So the front and back's area is 30. Now you find the area of both sides. They are both rectangle so the formula is A=BH.
A=BH
A=3x5
A=15
15x2=30
Now you find the area of the top and bottom. It is also a rectangle so you will use the same formula.
A=BH
A=3x3
A=9
9x2=18
Finally, you add all these measurements together adn that is the surface area.
This surface area of this rectangle prism is 78.
This answer us 16.97
you do square root of 288 and it will give you the answer of 16.97
Answer: 4=40 ! Its a pattern
Rice: .5(8) = 4kg (4000 g)
Popcorn: 150(12) = 1800 g
Total mass = mass of rice (4000 g) + mass of popcorn (1800g)
So...
Total mass = 5,800 g (or 5.8 kg)
