Question 211397
Let x = the number
x+6 = the "sum"
x-6 = the "difference"


The equation is:

(x+6)(x-6) = 189

x^2 -36 = 189


Since this is quadratic, set it equal to zero:
x^2 -36-189=0
x^2-225=0


There are two ways to solve this.  You can factor it:
(x-15)(x+15) = 0
x=15 or x=-15


Or you can use the square root method:
x^2 -225 =0
x^2=225
{{{x= sqrt(225)}}} or {{{x= -sqrt(225)}}}
{{{x = 15}}} or {{{x=-15}}}


R^2


Dr. Robert J. Rapalje, Retired
Seminole Community College