Question 387585: Could someone show me how to work this out. I am lost please go step by step.
-8q^2-2q+1=0
Thank you so much!
Answer by tara0066(31)   (Show Source):
You can put this solution on YOUR website! -8q^2-2q+1=0 This one may be tough for you to follow. I will do my best.
The first thing you want to do, since factoring will be a mess with that -8 out front, is to multiply your first term and your last term (AC) (-8)(1)=-8. Now we want to find two numbers that multiply to get -8 and add to get -2, which is your middle term. The numbers you need are (-4)(2) which meet both requirements. With these numbers you will replace your middle term.
-8q^2-4q+2q+1=0 If you look, the value hasn't changed at all. If you simplified it, you will get the original equation. Also, the order that you put them into the equation doesn't matter either. You could have listed them as +2q-4q and you would get the same answer in the end.
-8q^2-4q+2q+1=0 Now, we are going to break that equation into to parts and factor out what they each have in common.
-4q(2q+1)+1(2q+1) You should have matching sets left over. You have to pull something out of the second set, even if they have nothing in common, so it's just a +1, which if you would distribute it, it doesn't change the values at all.
(-4q+1)(2q+1)=0 You get one from the repeated set and the other comes from the junk you pulled out of both of the sets.
-4q+1=0
-4q=-1
q=1/4
2q+1=0
2q=-1
q=-1/2
Know this is alot to read but wanted to explain why we are doing what we are doing. Once you actually work it and know what to do it isn't too hard or long. Just takes alot to explain it when I can't simply write it down.
|
|
|
