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May 6, 2015

May 6, 2015

Posted by **kibodee** on Sunday, July 10, 2011 at 7:38am.

1) x^2=5x-6

2) 6x^2-20=-7x

3) 6x^2-7x=-2

- math -
**Henry**, Monday, July 11, 2011 at 5:03pm1. x^2 = 5x-6,

x^2 - 5x + 6 = 0,

(x-2)(x-3) = 0.

x-2 = 0.

x = 2.

(x-3) = 0,

x = 3.

Solution Set: x = 2, and 3.

2. 6x^2 - 20 = - 7x,

6x^2 + 7x -20 = 0,

Use AC Method:

A*C = 6*(-20) = -120 = -4*30 = -5*24 =

-6*20 = -8*15.

Select the factored pair whose sum =

the coefficient of x(7):

6x^2 - 8x+15x - 20 = 0,

Group the 4 terms into 2 factorable pairs:

(6x^2-8x) + (15x-20) = 0,

2x(3x-4) + 5(3x-4) = 0,

(3x-4)(2x+5) = 0,

3x-4 = 0,

3x = 4,

x = 4/3 = 1 1/3.

2x+5 = 0,

2x = -5.

x = -5/2 = -2 1/2.

Solution Set: x = 1 1/3, and -2 1/2.

3. Use same procedure as problem 2 and get:

x = 2/3, and 1/2.