Adam has a rectangular fish tank that measures 5 feet in length, 2 feet in width, and 3.5 feet in height. The tank is completely filled with water. It is time to clean the fish tank, and Adam decides that the best way to clean the tank is to drain the water from the tank by half. If 1 cubic foot of water is equal to about 7 gallons of water, how much water would Adam have to drain from the fish tank?
A.17.5 gallons
B.35 gallons
C.122.5 gallons
D.245 gallons

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.

a

step-by-step explanation: