SOLUTION: y2-4y-45=o I need help solving this my teacher went through it in class but i still don't get it please go through it step by step. Thank you :)

Question 434435: y2-4y-45=o
I need help solving this my teacher went through it in class but i still don't get it please go through it step by step. Thank you :)
Found 2 solutions by edjones, josmiceli:
Answer by edjones(8007) (Show Source): You can put this solution on YOUR website!
y2-4y-45=0
(y-9)(y+5)=0
y=9, y=-5
.
Ed
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
It depends on what method your
teacher was trying to show you
I'll use the method known as
"completing the square"

Add to both sides

Take of the coefficient of ,
square it, and add it to both sides

Each side is now a perfect square

Take the square root of both sides (both (+) root and (-) root)

(1)
and

(2)
-----------
You can rewrite (1) and (2) as:
(1)
(2)
Now you can factor the equation:

RELATED QUESTIONS
we are learning algebra in my 6th grade advanced class but i am not catching on to it... (answered by checkley75)
I need help with finding the slope because in math class today my teacher went over it... (answered by Alan3354,solver91311)
hey there, I really don�t know in which category this goes, but my teacher gave me this... (answered by josgarithmetic)
I need help solving this equation. (-1/2)^5 I've tried it in a calculator and i get... (answered by stanbon)
can you help me write an algebraic expression in words for these problems? 15-b, z-7,... (answered by kiljoy)
okay. today my teacher went over this, but I still do not understand it. She said to do... (answered by doukungfoo)
SOLVE THE SYSTEM USING THE GAUSS-JORDAN METHOD PROBLEM: x-y= 4 2x+y= 5 MY... (answered by MathLover1)
I've had a problem with math since 5th grade and just last yeat in 8th grade I've... (answered by askmemath)
My teacher went over these problems in class today. I know that I would set up a chart... (answered by stanbon)