Lets get all the information we need first.
A week has 7 days, you practice 30 min each day, so in a week you will practice a total time t of 30 min for 7 times, that is:
t = 7day(30 min/day)
t = 210 min
So in a week you will practice a total of 210 minutes.
The factor of this expression would be 2(x+1)
since there is always a decimal at the end of every value so :
= 262144.0
you move the decimal backwards if there is no decimal between the value. you place the decimal after the 1st digit, you will also count the digits you have passed :
= 2.62144 X 10^5
you passed 5 values so you put 5 in exponent form.
5.96 into a fraction = 596/100 or 149.25
$25.50
15% of 30 is 4.5 which if you subtract it'll make $25.50 <span />