Answer:
3 days
Step-by-step explanation:
The problem statement tells you that Kelly is there for 3 days.
Step 2: <span>Inverse Property of Addition
</span><span>any number added to its opposite will equal zero
</span>in this case + 20 - 20 = 0
answer
Inverse Property of Addition
The equation for monthly payment is b = 49.05M.
<u>SOLUTION:</u>
Given, a cellular family phone plan cost $49 per minute plus five cents per minute of long distance service. We have to write an equation for the monthly payment b when M minutes of long distance service are used.
Now, given that,
![\begin{array}{l}{\text { Monthly payment = } \$ 49 \text { per minute plus five cents per minute of long distance }} \\\\ {\Rightarrow \$ 49 \times \text { number of minutes }+\$ 0.05 \times \text { number of minutes of long distance }} \\\\ {\Rightarrow \mathrm{b}=49 \times \mathrm{M}+0.05 \times \mathrm{M} \rightarrow \mathrm{b}=49 \mathrm{M}+0.05 \mathrm{M} \rightarrow \mathrm{b}=49.05 \mathrm{M}}\end{array}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Bl%7D%7B%5Ctext%20%7B%20Monthly%20payment%20%3D%20%7D%20%5C%24%2049%20%5Ctext%20%7B%20per%20minute%20plus%20five%20cents%20per%20minute%20of%20long%20distance%20%7D%7D%20%5C%5C%5C%5C%20%7B%5CRightarrow%20%5C%24%2049%20%5Ctimes%20%5Ctext%20%7B%20number%20of%20minutes%20%7D%2B%5C%24%200.05%20%5Ctimes%20%5Ctext%20%7B%20number%20of%20minutes%20of%20long%20distance%20%7D%7D%20%5C%5C%5C%5C%20%7B%5CRightarrow%20%5Cmathrm%7Bb%7D%3D49%20%5Ctimes%20%5Cmathrm%7BM%7D%2B0.05%20%5Ctimes%20%5Cmathrm%7BM%7D%20%5Crightarrow%20%5Cmathrm%7Bb%7D%3D49%20%5Cmathrm%7BM%7D%2B0.05%20%5Cmathrm%7BM%7D%20%5Crightarrow%20%5Cmathrm%7Bb%7D%3D49.05%20%5Cmathrm%7BM%7D%7D%5Cend%7Barray%7D)
<em>Equation:</em>
An equation is a statement that the values of two mathematical expressions are equal <em>(indicated by the sign =)</em>
The equation should be 7x^2 -x-9=0