Answer:
Step-by-step explanation:
Given that,
The dimensions of an aquarium are 61 cm long, 30.5 cm wide, and 30.5 cm high.
The tank is filled to 80% capacity with water.
We need to find the water needed for this tank.
The volume of cuboid is given by :
As it is filled to 80% capacity, so,
So, 
of water is needed for this tank.
Answer: x = -4 or x = 7
Step-by-step explanation:
x^2 - 3x - 28 =/>
(factor)
(x^2 + 4)(x-7) = 0
x + 4 = 0 or x - 7 = 0
(subtract -4 from 0 and 7 from 0)
x = -4 or x =7
Answer:
x=28
Step-by-step explanation:
We can use similar triangles and proportions to solve this problem. Put the side of the small triangle over the same side of the larger triangle.
x 42
---------- = ----------
x+10 42+15
Simplify
x 42
---------- = ----------
x+10 57
Using cross products
57x = 42 (x+10)
Distribute
57x = 42x+420
Subtract 42x from each side
57x-42x = 42x-42x +420
15x = 420
Divide each side by 15
15x/15 = 420/15
x=28
