Answer:
X = 9, -1
Step-by-step explanation:
1, Factor it
(x-9) (x+1) = 0
2. Both of a factor will = 0
x-9 = 0
x+1=0
3. Solve
x=9
x=1
Answer:
x=45
Step-by-step explanation:
Since AB is a straight line, it is 180 degrees
AOE + EOF + FOD + DOB = 180
15+x+2x+120-2x = 180
Combine like terms
135 +x = 180
Subtract 135 from each side
135-135 +x = 180 -135
x = 45
Answer:

Step-by-step explanation:

Answer:
400 lb of salt
Step-by-step explanation:
Let us assume the water flows into the rank for x minutes.
There is an initial of 1000 gallons of water in the tank and water flows in through one pipe at 4 gal/min and through another pipe at 6 gal/min. In x minute, the amount of water in the tank = 1000 + 4x + 6x = 1000 + 10x
Water flows out at 5 gal/min, therefore in x minute the amount of water in the tank = 1000 + 10x - 5x = 1000 + 5x
The tank begins to overflow when it is full (has reached 1500 gallons). Therefore:
1500 = 1000 + 5x
5x = 1500 - 1000
5x = 500
x = 100 minutes.
1/2 lb salt per gallon flows into the tank at 4 gal/min and 1/3 lb of salt is flowing in at 6 gal/min, in 100 min the amount of salt that entered the tank = 4 gal/min × 100 min × 1/2 lb/gal + 6 gal/min × 100 min × 1/3 lb/gal= 400 lb
Therefore the amount of salt is in the tank when it is about to overflow = 400 lb of salt