Hi my name is Ken
I'm one of math tutors at Valencia College west campus
two things I like; good cigar, good math problem
Well I've already got the cigar, let's see what math problem we have today
Hi. Today we're going to look at solving a 
quadratic
with the quadratic formula specifically
we're going to look at something cause a
lot of students problem
and that's when they give you the equation out of order, meaning that the powers don't go from 
highest to lowest like we're used to seeing them
remember general form of a quadratic is ax squared  
plus bx plus c
so for instance the a is attached to
the x squared term, well some students would look at this equation and say because this is 
the first term this must be the letter a
but is not this is the a because it has to be the coefficient
attached to the x squared term. so the first thing I'm going to do on this  I'm going to rewrite this
and put it back into the form it's supposed to be in
which is 2x squared plus 3x minus 7
and now you can easily see that our a is 2 b is 3 and c is -7
so let's go ahead and solve this. remember the quadratic formula
is negative b plus or minus the  square root
b squared - 4 ac 
all over 2a. Big formula but we use this thing a lot so you should have it memorized
lets go plug our numbers into it; remember b is 3.
-3 plus or minus the square root b squared 
3 squared is 9 minus 
four times a is 2 times c is
negative 7
and this is all over 2a  which is 2 times 2 so let's figure this out
we have - 3 plus or minus the square root of 9 remember negative times negative makes a positive
4 times 2 is 8 times 7 is 56 over 2 times 2 
is four. Come over here I'm getting a lttle to low
so -3 plus or minus the square root 
9 plus 56 is 65 over 
four and I don't think that reduces so this is our final answer  right here
-3 plus or minus the square root of 65 over 4
so just remember if they give you
one that is out of order, rewrite it in terms of going from the
highest power of x down to just the number
and then solve it from there. If you have any questions come see me in the tutoring center
