Answer:
Step-by-step explanation:
Question 9
<u>From the previous question we know that:</u>
- The rate of draining = 2/3 gal/min
- Remaining water = 5 gal
<u>Time to empty the tank is:</u>
- 5 : 2/3 =
- 5 * 3/2 =
- 15/2 =
- 7 1/2 minutes
The "rule of 72" says that the doubling time in years is approximately 72 divided by the interest rate in percent. To make the money grow by a factor of 4 requires that it double twice, so will take twice as long as the period to double once.
2×72/11.3 ≈ 12.7 . . . . years
_____
The "rule of 72" is an approximation. The actual quadrupling time for this interest rate and compounding is about 12.6 years. (The actual product of doubling time and nominal interest rate is about 71.25.)
Answer: c) -4
Step-by-step explanation:
Get the variables on one side of 3x+y=-2x+8 and the constants on another side:
3x+y=-2x+8
(3x+y)+2x=(-2x+8)+2x
5x+y=8
Now, multiply 5x+y=8 by -2:
-2(5x+y=8)
-10x-2y=-16
Add this equation to -3x+2y=-10:
(-10x-2y=-16)+(-3x+2y=-10)
-13x=-26
x=2
Plug x=2 into -3x+2y=-10:
-3(2)+2y=-10
-6+2y=-10
2y=-4
y=-2
Therefore, (2, -2) is the solution to the system of equations, so xy=(2)(-2)=-4
Answer:
x = -0.8
<CAD = -8
Step-by-step explanation:
10x + 4 = 5x - 4 (Clean up)
10x = -8 (Divide each side by 10)
x = -0.8
<CAD = 5x - 4
<CAD = 5(-0.8) - 4
<CAD = -4 - 4
<CAD = -8
