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  • May 29, 2006, 12:41 PM
    kerensak
    Algebra help! - test tomorrow! (help!)
    There are a few problems that I am having trouble with. I hope someone can help me figure them out (& please explain how you got them).

    Robin is having her yard landscaped. She obtained an estimate from two landscaping companies. Company A gave an estimate of $210 for materials and equipment rental plus $65 per hour for labor. Company B gave an estimate of $280 for materials and equipment rental plus $55 per hour for labor. Determine how many hours of labor will be required for the two companies to cost the same.
    EDIT: I got 7 hours.
    x=hours
    210 + 65x = 280 +55x
    10x = 70
    x=7



    I absolutely hate these:
    The formula F = 18t2 - 200t + 938 models the number of convicts in a city t years after 1985. How many convicts were there in 1995?



    Usually I have no problem with these but I've worked it like five times:
    Find (fg)(-5) when f(x) = x+4 and g(x)=4x2+18x-1
    Edit: I got an answer.

    (x+4)(4x2 +18x-1)
    4x3+18x2-x+16x+72x-4

    4(-5)^3 + 18(-5)^2 - (-5) + 16(-5)^2 + 72(-5) - 4
    -500 + 450 +5 + 400 - 360 - 4
    =-9


    The answers are either:
    -9, -81, 66, -891


    Last, but not least:
    The length of a rectangular room is 6 feet longer than twice the width. If the room's perimeter is 144 feet, what are the room's dimensions?
    EDIT: I got the answer

    x=width
    x+6=length

    2(x+6) + 2x = 144
    2x + 12 + 2x = 144
    4x = 132
    x = 33

    33 + 6 = 39 (LENGTH
    33ft x 39ft



    Find the domain of f/g when f(x) =4x2 + 4x - 4 and g(x) = x-2
    Edit: I found the answer

    {x|x is a real number and x does not equal 2}


    MOST IMPORTANTLY, I JUST WANT TO KNOW HOW TO GET TO THE ANSWER. JUST GIVING ME THE ANSWERS AREN'T GOING TO HELP. :eek:
  • May 29, 2006, 01:53 PM
    CaptainForest
    Robin
    Correct, 7 hours

    Convicts in City
    F = 18t2 - 200t + 938

    the number of convicts in a city t years after 1985

    in 1995 = ?

    1995 is 10 years after 1985

    So,
    F = 18t2 - 200t + 938
    F = 18(10)2 – 200(10) + 938
    F = 738

    Therefore, there were 738 convicts there in 1995.

    Rectangle Room
    Length = 2w + 6

    Perimeter = 144

    144 = 2w + 6 + 2w + 6 + w + w
    144 = 6w + 12
    6w = 132
    w = 22

    Therefore, the width is 22 feet, the length is 22x2 + 6 = 50 feet

    Perimeter = 50 + 50 + 22 + 22 = 144

    Therefore, the dimensions are

    Width = 22 feet
    Length = 50 feet
  • May 30, 2006, 06:20 AM
    fredg
    Hi,
    I might suggest that don't do as I did when in high school; don't wait until the day before to try learning how to do Algebra. I was a High School math teacher for 13 yrs, teaching among other subjects, Algebra.
    I had "extra help" classes for students after school, and many, many took advantage of it. Please talk with your teacher about getting some help, or maybe he/she can suggest someone who can help you.
    Best of luck.

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