00:01
This question asks us to factor this quadratic in order to solve the equation.
00:06
And so we can do this by using something called product sum and guess.
00:12
And before we begin, we just need to note what our a, b, and c terms are in this equation.
00:21
So our product column is always going to be our a times our c term.
00:27
In this case, it's 8 times negative 9, which gives us negative 72.
00:32
And our sum is always going to be our b term, which in this case is six.
00:38
And for our guest column, we want to think of two numbers that will multiply to negative 72, but also add to a positive six.
00:46
And so we just start listing off factors of 72.
00:50
And the first one that comes to my mind is 9 and 8, but we know that isn't going to add to 6, but 12 and 6 will.
00:59
If we make the 6 and negative, it will add to a positive 6, also multiply to a negative 72.
01:08
And so we can rewrite the quadratic as 8x squared times minus 6x, and then 12x minus 9, and said that both equal to 0.
01:26
So i broke our 6x term into the factors that we got from product summing guess...