Answer:
The sum is 493.4
Step-by-step explanation:
In order to find the value of the sum, you have to apply the geometric series formula, which is:

where i is the starting point, n is the number of terms, a is the first term and r is the common ratio.
The finite geometric series converges to the expression in the right side of the equation. Therefore, you don't need to calculate all the terms. You can use the expression directly.
In this case:
a=40
b= 1.005
n=12 (because the first term is 40 and the last term is 40(1.005)^11 )
Replacing in the formula:

Solving it:
The sum is 493.4
2 times 3 times 4 times 4 times 5 equals 480
Answer:

Step-by-step explanation:
All of the sides are the same length.



The change of base formula allows you to write a logarithm in terms of logarithms with another base. It follows this pattern,

where a≠1 and b≠1
Assigning the base to be 7,

I hope I was able to answer your question. Have a good day.
Answer:
a. Not proportional
b. Proportional;
k = ⅞
Step-by-step explanation:
A proportional relationship is usually represented in the format, y = kx. k here represents constant of proportionality. This shows that x and y are directly proportional.
a. y = -2x + 9 is not a proportional equation.
b. y = ⅞x is a proportional equation.
Constant of proportionality: k = ⅞