SOLUTION: Solve by factoring: y2 + 2y = 8 please PLEASE help me and please show your work. thank you so much ~April

Algebra ->  Expressions-with-variables -> SOLUTION: Solve by factoring: y2 + 2y = 8 please PLEASE help me and please show your work. thank you so much ~April      Log On


   

Question 711751:
Solve by factoring:
y2 + 2y = 8
please PLEASE help me and please show your work.
thank you so much
~April
Answer by tutor_paul(519) About Me  (Show Source):
You can put this solution on YOUR website!
y%5E2%2B2y=8
First step is to equate to zero. Do this by adding -8 to both sides of the equation:
y%5E2%2B2y-8=8-8
Simplify:
y%5E2%2B2y-8=0
Now you can factor this. You have to think to yourself "What factors of -8, when combined, add up to 2?" Well, -2 and 4 come to mind. Use these as the factors:
%28y%2B4%29%28y-2%29=0
Now you equate each term to zero and solve for y:
y%2B4=0
highlight%28y=-4%29
y-2=0
highlight%28y=2%29
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Good Luck,
tutor_paul@yahoo.com