The answer would be: He spent 17 hours on the phone
Explanation: $826.20 - $725= $101.2 - $40= $61.12 / $3.60= 17hrs
D. 21cm because you divide all sides by 2 then get your slope form and multiply by seven
we have

we know that


so



the answer is in thousandths, because the denominator of the multiplication of the two fractions is one thousand
Answer: 
Step-by-step explanation:
We know that the general form of the exponential decay formula is
, where y is final amount remaining after t time, A is the original amount and r is the rate of decay
Now, the ratio of strontium-90 remaining, p , as a function of years, t , since the nuclear accident. 
Hence, the ratio of remaining since the nuclear accident is 
Answer:
13
Step-by-step explanation:
use the Pythagorean theorem; five squared plus twelve squared is equal to the missing side squared, 25+144=169, the sqrt of 169 is 13