Answer:
We have the equation:
P(t) = 100 - 10*t
where t is the number of hours.
at t = 0, we have:
P(0) = 100 - 0 = 100
so at the initial time, we have 100% of the battery power.
Now with this equation we can find the numbers of hours that we have left in our phone, this is finding the time t at which the power left is equal to zero:
P(t) = 0 = 100 - 10*t
10*t = 100
t = 100/10 = 10
So the battery power will last for 10 hours.