To find the sum of an infinite geometric series having ratios with an absolute value less than one, use the formula, S=a11−r, where a1 is the first term and r is the common ratio.
Answer:
12b + 36
Step-by-step explanation:
multiply the outside of the bracket by the inside
12(b + 3)
12b + 36
we are given
speed is 850mi/h
we know that
1 mile =1609.34 metre
1 hour = 3600 second
now, we can replace 1mi and 1hour

now, we can solve it
379.98306
...........Answer