? asked in 科學及數學數學 · 10 years ago

new york me44 math problems

1.which of the following is the sum of the solutions of 4x^2-35x-9=0?

(F)-8

(G)8

(H)8.75

(J)9.25

solve this question by factoring

1. w^2-8w=0

please answer as soon as possible cos i have to hand this hw to my teacher tomorrow!!!

Update:

can you explain in more details?

Update 2:

like the process, step by step

MY MATH IS TERRIBLE!

Update 3:

THANKS A LOT!!

2 Answers

Rating
  • 10 years ago
    Favorite Answer

    1.Factorize 4x^2-35x-9 first.

    Let 4x^2-35x-9 be (4x+a)(x+b).

    Then, split -9 into two numbers which only can be 1,9 or 3,3.(ignore negative signs first)

    Let us try1,9 first.

    The answer will be(4x+1)(x-9).

    Either 4x+1 or x+9 equals to 0.

    If 4x+1=0, x equals to -1/4.

    If x-9=0, x equals to 9.

    9+(-1/4)=8 3/4.

    2.w^2-8w=0

    Take away the common factor, it becomes to w(w-8)=0

    so either w=0 or w-8=0

    If w=0, w=0.

    If w-8=0,w=8

    So,w can be 0 or 8.

  • 10 years ago

    4x^2-35x-9=0

    (4x+1)(x-9)=0

    x = -1/4 (-0.25) or x = 9

    their sum is : -0.25 + 9 = 8.75

    +++

    w^2 - 8w = 0

    w(w - 8) = 0

    w = 0 or w = 8

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