00:01
So we're going to use the factor by grouping method to factor this problem and find the zeros.
00:07
So let's look at our first two terms here.
00:09
Well, if we factor out, if we factor out an x squared, what we have is 2x, 2x minus 1.
00:18
And so for the next two terms, if we factor out a negative 9, what we're left with is x minus 1, or rather 2x minus 1.
00:30
So since these two are now equal, these two are now equal, we can say we have x squared minus 9 times 2x minus 1.
00:40
And so we can split this up using difference of squares.
00:45
So we have x minus 3 times x plus 3 times 2x minus 1.
00:53
And so now we know we have zeros at 3, negative 3, and then at 1 half, at 1 half...