Anonymous
Anonymous asked in Education & ReferenceHomework Help · 1 decade ago

Can anyone solve this math problem?

factor:

x^2 - 9x + 18

3b^2 - 7b + 4

13 Answers

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  • 1 decade ago
    Favorite Answer

    What you need to remember is the simple formula for the problems you're attacking:

    (ax - b)(cx - d) = acx^2 - x(bc + da) + bd

    1) So let's attack the first problem:

    x^2 - 9x + 18

    Because there is no integer in front of x^2, we know that a and c are only 1 and your new factor formula looks like:

    (x-b)(x-d)

    Now the question is, what two numbers can you multiply together to make 18, yet add together to make -9? Start by factoring out 18:

    18 = (-1, -18), or (-2,-9), or (-3,-6).

    Only 3 and 6 can combine to make -9, and since the values for a and c are the same, it doesn't matter where you place each number. Your answer is therefore:

    x^2 - 9x + 18 = (x-3)(x-6)

    2) Your next question is a little more difficult, since there is an integer before the b^2 value. But 3 only has one pair of factors: (3,1), so you can plug those into your factor equation:

    (3b - ?)(b - ?)

    Now the second part is a bit trickier. You need two numbers that when multiplied equal 4, but you have to place them in the right place so that one of them will multiply with 3 before being added to equal -7. So let's factor out 4's pairs:

    4 = (-1, -4), or (-2, -2)

    At this point, you can try plugging in each pair. If you plug in the second pair, you end up with -8b as a middle term. So you know it has to be the first pair (-1,-4). If you place the -1 with the 3b, you'll end up with -13b. But if you place the -4 with the 3b, you'll end up with -7b, and your answer!

    3b^2 - 7b + 4 = (3b-4)(b-1)

    Hope this helps, and remember that if your middle terms were +9x and +7b, your factors would be positive!

  • Anonymous
    1 decade ago

    It factors to (x-3)(x-6)=0 x=3,6

    (3b-4)(b-1)=0 b=1, b=4/3

  • 4 years ago

    2x + 2y = 20 utilising the simultaneous approach 2x - 2y = 4 ____________ 4x = 24 ( divide through 4) x = 6 replace x in between both equations 2x + 2y = 20 2 (6) + 2y = 20 12 +2y = 20 2y = 20 - 12 2y = 8 (divide through 2) y = 4 answer : X = 6 , Y = 4

  • its a factor problem not a solve and its

    (x-3)(x-6)

    (3b-4)(b-1)

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  • 1 decade ago

    (x-6) (x-3)

    (3b-4) (b-1)

    If you want help knowing how i got this just send a message and i'll try to explain it to you better.

  • 1 decade ago

    x=3

    x=6

    b=1

    b=1.3333

  • Anonymous
    1 decade ago

    As Mr. P. Nuss would say, "Let me take a whack at it!"

  • 1 decade ago

    you didn't give an equals sign so there is no actual problem

  • 1 decade ago

    (x-6)(x-3)

    ???

  • Anonymous
    1 decade ago

    i cant understand u r question properly

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