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2. write in vertex form Y= X^2-12X+40

3. solve by completing the square X^2+6X-7=0

4.solve the equation 2X^2+8X-14=0


please write the number of the question before the answer
thank you and please help

2007-04-05 03:38:30 · 2 answers · asked by Anonymous in Education & Reference Homework Help

2 answers

1. Standard form is y = ax^2 + bx + c, so you have to expand the term in parentheses, and then combine like terms:

y = -3(x + 1)^2 + 5
y = -3(x^2 + 2x + 1) + 5
y = -3x^2 - 6x - 3 + 5
y = -3x^2 - 6x + 2

2. Vertex form is the form you were given in (1). In this case, you have to complete the square to get it done:

y = x^2 - 12x + 40
y = (x^2 - 12x + 36) + 40 - 36
y = (x - 6)^2 + 4

3. Completing the square is the method used above for (2):

x^2 + 6x - 7 = 0
x^2 + 6x = 7
x^2 + 6x + 9 = 7 + 9
(x + 3)^2 = 16
x + 3 = 4
x = 1

4. You can do this several ways, but using the quadratic formula will give you an exact answer:

2x^2 - 8x - 14 = 0
x^2 - 4x - 7 = 0

x = [-b +/- sqrt(b^2 - 4ac)] / 2a
x = [4 +/- sqrt((-4)^2 - 4(1)(-7))] / 2(1)
x = [4 +/- sqrt(16 + 28)] / 2
x = [4 +/- sqrt(54)] / 2
x = [4 +/- 3sqrt(6)] / 2

2007-04-05 04:48:22 · answer #1 · answered by igorotboy 7 · 0 0

that's 3x -y +2 =0. you in basic terms subtract the y from the left over to the superb, making it a unfavorable. leave the two as an excellent nevertheless, in view which you do no longer would desire to do something with it. Cheers - wish this helped =)

2016-12-20 06:40:52 · answer #2 · answered by Anonymous · 0 0

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