help with algebra questions please (2 questions)?
September 8th 2009
Im not good in math and these 2 question have me stumped!
Given the Function defined by g(x)=5X-8, find g (1/5)
I dont know what to do! can you show me and explain?
also……
The cost of producing a newsletter is an initial charge of $100.00 for formatting and editing plus $0.25 for printing each copy. Answer the questions below.
a) Express the cost C(x) of printing the newsletters as a function of the number of copies printed, x.
C(x)=__________????? please explain and help
b) obtain values for the function when X=0, X=100, x=200, and x=300
C(0)=______???? i am going to assume this is 0
C(100)=_________
C(200)=__________
C(300)=_________
September 8th, 2009 at 10:53 pm
g(1/5)=5(1/5)-8=-7
C(x)=100+.25x
C(0)=100, C(100)=125
C(200)=150, C(300)=175
September 8th, 2009 at 10:59 pm
i’ll try at least explain it a bit, not like the guy above lol
ok first:
g(x)=5x-8 find g(1/5)
so they’re basicaly telling you to substitute 1/5 for x in g(x)=5x-8 .So this will give: g(1/5)=5(1/5)-8
= -7
see? you’ve just put 1/5 in where the x use to be and worked it out.
the second one goes like this:
C(x)=0.25x+100
C means Cost, so e.g what is the cost if you get 43 copies = C(43)
here you know that for every copy of newsletter it costs $0.25, so to know how much it would cost for say, 5 copies, you would times $0.25 by 5, wouldn’t you? So to put this in function form: we don’t know how many copies we’re gonna print yet, so we use ‘x’ as this unknown number. 0.25x effectively means 0.25 times ‘number of copies’.
now that you know this we just add 100, because no matter how many copies you have, we definitely know that we are going to be charged $100 in addition in the 0.25 times no. of copies.
now with substituing the numbers, all you do is the same as the very first one.
so C(0)=0.25(0)+100
= $100 (you’ve just put the 0 in place of where the x use to be)
and
C(100)=0.25(100)+100
=25+100
=$125
I’m sure you can figure out the rest, hope this helped