What are two numbers which multiply to make #-9450# and add to make #-15# ?

1 Answer
Jun 6, 2018

#-105 xx 90 = -9450#

#-105 +90 = -15#

Explanation:

One number has to be positive and one has to be negative to give a negative product.

Factors which differ by #15# are close to the square root of a number. They will be about #7# bigger or smaller than the square root.

#sqrt 9450 =97.211...#

Try numbers less than #97#

#9450 div 95 = 99.47" "larr# does not work
#9450 div 94 = 100.53" "larr# does not work
#9450 div 90 = 105" "larr# These are the factors

#-105 xx 90 = -9450#

#-105 +90 = -15#