If f(x)=x+7and g(x)=1/x-13, what is the domain of (f•g)(x)

(-∞, 0)∪(0, ∞)

Step-by-step explanation:

You are given the functions f(x) and g(x).  Now, you have to find (f*g)(x).  To do this, you have to multiply the two functions.

f(x) = x + 7

g(x) = 1/x - 13

(f*g)(x) = (x + 7)(1/x - 13)

(f*g)(x) = -13x + 7/x + 1 - 91

(f*g)(x) = -13x + 7/x - 90

The domain has to include all of the x-values that will produce a rational number.  So, look at where the x's are locate

-13x:  You could put any rational number into this value and still have a rational number.

7/x:  For this value, you cannot have 0 as an x-value.  Every other number is fine.

This means that the domain will be (-∞, 0)∪(0, ∞).  

You use parentheses and not brackets for the zero side because you don't want to include zero in the domain, but you do want to include all of the other numbers around zero.  There are no brackets on the infinity side because infinity isn't a number.  The ∪ symbol is used to combine domains.

the answer is 489

step-by-step explanation:

2 & 7

step-by-step explanation:

he climbs 300 ft/hr at a constant rate. the peak is at 1,500 ft.

when going up, he reaches 600 ft in 2 hours. remember, that he is going in a constant rate. divide 600 with 300:

600/300 = 2

assuming that he takes the same route back (meaning that it's a 1500 ft route back, you can solve.

note also that you are solving when he gets back to 600 ft after he reaches the peak.

first, find the amount of hours it takes to get up the peak. divide the total amount (1500), with the ft/her (300) to get the amount of hours (x):

1500/300 = x

x = 5

it takes jamie 5 hours to get up. now, he is returning down, and reaches 600 (his current destination). remember that he climbs at a constant 300 ft/hr. divide 600 with 300:

600/300 = x

x = 2

now add the two numbers together.

x = 5 + 2 = 7

jamie takes 7 hours to go up the mountain and reach his current position when descending.

(total amount/constant rate) = (time).

remember that it is a constant rate, so in total, when he gets back down the mountain, it will take the same amount of time as when he goes up. the total amount for the round trip is: 5 + 5 = 10.

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