Solve the following equation,

Question

Solve the following equation.

 

 

   2

x      - 5x - 6 = 0

 

x = ? ( Use a comma to separate the answers as needed)

 

 

 

Answer 1

Hi Keith;

x²-5x-6=0

For the FOIL...

FIRST must be (x)(x)=x²

OUTER and INNER must add-up to -5x.

LAST must be (6)(1) or (1)(6) or (2)(3) or (3)(2) and one number must be negative to render the product of -6.

(x-6)(x+1)=0

Let's FOIL...

FIRST...(x)(x)=x²

OUTER...(x)(1)=1x=x

INNER...(-6)(x)=-6x

LAST...(-6)(1)=-6

x²+x-6x-6=0

x²-5x-6=0

(x-6)(x+1)=0

Either or both parenthetical equation(s) must equal zero...

x-6=0......x+1=0

x=6........x=-1

 

Let's check our results...

x² - 5x - 6 = 0..............x² - 5x - 6 = 0

6²-[(5)(6)]-6=0...........-1²-[(5)(-1)]-6=0

36-30-6=0...................1+5-6=0

0=0..............................0=0