z2 + 8z – 20 = (z – 2)(z + __)

-8
20
-10
10

Question

z2 + 8z – 20 = (z – 2)(z + __) 
  
 -8 
 20 
 -10 
 10

campbell_st · Answer

what are the factors of -20 that add to 8... the larger factor is positive. 

you are told the smaller factor is -2

what do you think...?

anonymous · Answer

Im thinking 20 but leaning towards 10 as well

campbell_st · Answer

well look at this   -2 x 10 = -20

                           -2 + 10 = 8

so I'd think you should ignor 20... and think strongly about 10

anonymous · Answer

Ok I was confused on them 2 and something kept telling me to go with 10 but then that 20 came into my mind. Algebra is very confusing to me trying to comprehend this stuff but thankyou :)

campbell_st · Answer

its just a case of working with it... remember the last term -20 is the product of 2 numbers... 

the coefficient of x is the um of thise 2 numbers... 

hope it helped...

anonymous · Answer

yes it did once again thankyou appreciate the help