The correct answers are, <u>C and D</u>
Answer:
The function is A = 10√r
Step-by-step explanation:
* Lets explain the meaning of direct variation
- The direct variation is a mathematical relationship between two
variables that can be expressed by an equation in which one
variable is equal to a constant times the other
- If Y is in direct variation with x (y ∝ x), then y = kx, where k is the
constant of variation
* Now lets solve the problem
# A is varies directly with the square root of r
- Change the statement above to a mathematical relation
∴ A ∝ √r
- Chang the relation to a function by using a constant k
∴ A = k√r
- To find the value of the constant of variation k substitute A and r
by the given values
∵ r = 16 when A = 40
∵ A = k√r
∴ 40 = k√16 ⇒ simplify the square root
∴ 40 = 4k ⇒ divide both sides by 4 to find the value of k
∴ 10 = k
- The value of the constant of variation is 10
∴ The function describing the relationship of A and r is A = 10√r
The explicit formula is a(n) = 15(n – 10)
<u>Solution:</u>
Given, a term a(19) = 135 and common difference d = 15
We have to find the explicit formula.
Now, we know that, a(n) = a + (n – 1)d where a(n) is nth term, a is first term, d is common difference,
So, for a(19)
Now, we know that, an explicit formula is an expression for finding the nth term,
So, in our problem, expression for finding nth term is a + (n – 1)d
Hence, the explicit formula is a(n) = 15(n – 10).
Answer:
B:5x
Step-by-step explanation:
It would be B because if you add all the sides together you would get 5x and 5x is B
