Step-by-step explanation:
Given
x² - 9x + 20 = 0
x² - ( 4 + 5) x + 20 = 0
x² - 4x - 5x + 20 = 0
x ( x - 4 ) - 5 (x - 4 ) = 0
(x - 4 ) ( x - 5 ) = 0
Either
x - 4 =0
x = 4
or
x - 5 =0
x = 5
x = 4 and 5
Hope it will help :)

Answer:
Your question is VERY hard to read so I'm gonna take the points and go..
It pretty much looks like a one to one function. Plot the graph then draw a horizontal line,if the line touches the graph at just one point then it is
The answer would be 44.7 not 44.5