Answer:
9
Step-by-step explanation:
This means that 9/(9+72)=(3x-20)/(3x+36), or 1/9=(3x-20)/(3x+36). Cross-multiply to get that 27x-180=3x+36, so 24x=216, and x=9.
<span>Rate of pump A: 1/8 of a pool per hour
Rate of pump B: 1/9 of a pool per hour
Combined rate: 1/8+1/9 = 17/72 +1/9 = 25/72
So if they work together, the two pumps have a combined rate of 25/72 of a pool per hour (i.e in one hour, the two pumps will empty 25/72 of the pool)
</span><span>But we want to empty ONE pool (not 25/72 of one). So we need to multiply 25/72 by some number x to get 1.
</span>
<span>Now solve for x
x=2.88
</span><span>It will take the two pumps 2.88 hours to empty the pool.
2 hours 52 minutes 50 seconds</span>
A rational number is simply a term that can be expressed as a fraction. Otherwise, that is an irrational number. So, you can use a calculator to verify if the number is rational or not.
The key characteristic of an irrational number is when it contains a long line of decimal places. For example, the term π and the Euler's number e are irrational numbers. The exact values of π and e are 3.14159 and <span>2.71828182846, respectively. In reality, those decimal places go on a long way. Particularly, </span>π<span> has a total of 2.7 trillion digits. Numbers inside radicals or roots can also be irrational numbers. For example </span>√3 is irrational because it is equal to 1.732050808. However, not all radicals are irrational. For example √15.3664 is equal to 98/25 or 3.92. That is a rational number. So, therefore, use the calculator to know the exact value of the term to properly distinguish rational from irrational.
To translate y - 5 into words:
a number y is decreased by 5
i hope this helps!!
