Since

, and you have a corresponding term in the given Riemann sum of

, you know the integral is being taken over an interval of length 5, so you can omit the second choice.
Next,

corresponds to

with

. The fact that

alone tells you that the interval of integration starts at 3, and since we know the interval has length 5, that leaves the first choice as the correct answer.
Solve whats in the parentheses first
5k+25+4<21+6k
5k+29<21+6k
plug in a number in k for both sides
5(1)+29<21+6(1)
5+29<21+6
34<27
5(2)+29<21+6(2)
10+29<21+12
39<33
so 5(k+5)+4 is greater than 21+6k
To solve this relationship simply make them equal to each other and find the correct value to multiply both the top and cotton numbers and solve,
In this case because of the initial ratio of 1:9, if the bonsai ficus is 6 then 54 inches would be the full size.
Prime factorization means that we divide 90 by prime numbers only.
90 ÷ 2 = 45
45 ÷ 3 = 15
15 ÷ 3 = 5
2 x 3 x 3 x 5 = 90
2 x 3² x 5 = 90
or 2,3,3,or 5
What are the answer choices