Question

1. Jeff writes comic strips for a local newspaper. The number of comic strips he creates is represented by the function f(x) = 3x, where f(x) gives the number of comic strips and x is the number of work hours he puts in, which varies day to day. If he puts in {3, 4, 6, 7, 9} work hours, how many comic strips can he write?
2. If the range of the function f(x)= 5x − 3 is {-13, -8, -3, 12, 17}, what is its domain?

3. The number of hours required to do a painting job is represented by the function f(x)=2x , where f(x) gives the number of hours and x is the number of painters doing the job. How much time will {4, 10, 14, 16, 18} workers take to do the job?

Answer 1

1. f(x) = 3x
    f(3) = 3(3) = 9
    f(4) = 3(4) = 12
    f(6) = 3(6) = 18
    f(7) = 3(7) = 21
    f(9) = 3(9) = 27
    he can write {9,12,18,21,27} comic books

2. range is y values....f(x) is y.....therefore, range is f(x)...domain is x values
    f(x) = 5x - 3
    -13 = 5x - 3.....-13 + 3 = 5x....-10 = 5x.....x = -2
    -8 = 5x - 3....-8 + 3 = 5x.....-5 = 5x......x = -1
    -3 = 5x - 3....-3 + 3 = 5x....0 = 5x.....x = 0
    12 = 5x - 3....12 + 3 = 5x....15 = 5x.....x = 3
    17 = 5x - 3....17 + 3 = 5x....20 = 5x....x = 4
    so the domain is { -2,-1,0,3,4}

3. f(x) = 2x
    f(4) = 2(4) = 8
    f(10) = 2(10) = 20
    f(14) = 2(14) = 28
    f(16) = 2(16) = 32
    f(18) = 2(18) = 36
    time it will take in hrs { 8,20,28,32,36}