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.
Hello,
f'(x) = sin(x) - 65 → f(x) = -cos(x) - 65x
10 times as many as a number is 10 × the number.
10 times as many as 1 ten is 10 × 10 = 100
10 times as many as 1 hundred is 10 × 100 = 1000
Therefore, 10 times as many as 1 hundred is 10 hundreds or
10 times as many as 1 hundred is one thousand.
