Answer:
The inequality for this would be n ≥ 20.
We know this because it must be larger than 40. We also know it can possibly be equal because the statement says "at least".
Step-by-step explanation:
Answer:
D
Step-by-step explanation:
Answer:
(5a - [2b - 7c]) and (5a + [2b + 7c])
Step-by-step explanation:
Factor 25a^2 - 4b^2 + 28bc - 49c^2.
Note that - 4b^2 + 28bc - 49c^2 involves the variables b and c, whereas 25a^2 has only one variable. Thus, try to rewrite - 4b^2 + 28bc - 49c^2 as the square of a binomial:
- 4b^2 + 28bc - 49c^2 = -(4b^2 - 28bc + 49c^2), or
-(2b - 7c)^2.
Thus, the original 25a^2 - 4b^2 + 28bc - 49c^2 looks like:
[5a]^2 - [2b - 7c]^2
Recall that a^2 - b^2 is a special product, the product of (a + b) and (a - b). Applying this pattern to the problem at hand, we conclude:
Thus, [5a]^2 - [2b - 7c]^2 has the factors (5a - [2b - 7c]) and (5a + [2b + 7c])
Answer:
C
Step-by-step explanation:
The n th term formula of a geometric sequence is
= a 
where a is the first term and r the common ratio
Using the second and fourth term, then
ar = 6 → (1)
ar³ = 54 → (2)
Divide (2) by (1)
= 
= 9
r² = 9 ⇒ r = 
= 3 → C
Answer:
a + 
b
Step-by-step explanation:
