To x^2 - 4x - 45, find equivalent expression
Find 2 numbers m,n such that
m +n = -4
m - n = √ (-4)^2 - 4•(-45) = √(16 +180) = √196
m- n = √196 = 14
Now solve the system 2x2, add both equations
m + n + m -n = -4 + 14 = 10
then 2m = 10 , So then m= 10/2= 5
Now rest to find n
m + n = -4 then n = -4- m = -4-5= -9
n= -9
Now write equation
(x+m)•(x+n) = (x + 5) •( x - 9)
this is an equivalent expression
