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+10
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avatar+1023 

Factor x^2-8x-48

 Nov 24, 2015

Best Answer 

 #3
avatar+118608 
+20

Hi Olivia,

Thanks guests, 

 

I just want to discuss this a bit more  :))

 

Factor         \(x^2-8x-48\)

 

Like guest 2 said you need 

2 numbers that multipy to -48 and add to -8

 

Think about the multiply first.  

They multiply to a negative number so one must be negative and one must be positive.

 

Now they add to a negative SO the 'bigger' one is negative.

Mmm

So what multiplies to -48  where the 'bigger' one is negative.

possibilities are  

1 and -48,      

2,and -24,    

 3 and -16,    

4 and -12,      

6 and -8

which of these add to -8?     4 and -12  that the only one. 

so

x^2-8x-48 = (x+4)(x-12)             cool

 Nov 24, 2015
 #1
avatar
+10

x-12 ) ( x +4

 Nov 24, 2015
 #2
avatar
+15

Factor the following:
x^2-8 x-48

The factors of -48 that sum to -8 are 4 and -12. So, x^2-8 x-48 = (x+4) (x-12):
Answer:  (x+4) (x-12)
 

 Nov 24, 2015
 #3
avatar+118608 
+20
Best Answer

Hi Olivia,

Thanks guests, 

 

I just want to discuss this a bit more  :))

 

Factor         \(x^2-8x-48\)

 

Like guest 2 said you need 

2 numbers that multipy to -48 and add to -8

 

Think about the multiply first.  

They multiply to a negative number so one must be negative and one must be positive.

 

Now they add to a negative SO the 'bigger' one is negative.

Mmm

So what multiplies to -48  where the 'bigger' one is negative.

possibilities are  

1 and -48,      

2,and -24,    

 3 and -16,    

4 and -12,      

6 and -8

which of these add to -8?     4 and -12  that the only one. 

so

x^2-8x-48 = (x+4)(x-12)             cool

Melody Nov 24, 2015
 #4
avatar+1023 
+15

Thanks, you guys!!!!coolangelcheeky

 Nov 24, 2015

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