Video Gallery

Lesson 5-3 Solve by Factoring - when the leading coefficient is not 1

Go to Video Gallery Added Sep 19, 2017 •

Copy this URL:
Embed code:	<iframe class="edlio-embed-player" type="text/html" width="640" height="360" src="//colliervillehs.colliervilleschools.org/apps/embed/?v=157276" frameborder="0" allowfullscreen></iframe> Change dimensions

Go HD

Use the "slide and divide" method to factor, then solve.

Show Transcript

okay we're asked to solve this problem by factoring and noticed that we have a leading coefficient the first thing that we want to do is make sure that the equation equals 0 on the right hand side which it does and then we are going to start factoring the problem so we're going to take our leading coefficient the six we're going to multiply it to the end so our new equation are new expression is going to be at squared plus 7x minus 18 so we want to find two factors of -18 those are things that multiply to give us 18 and we want them to have a sum of positive stuff so if I have a product that's negative then that means I need one positive number and one negative number working together to give us a negative product and since the some number is a positive number we want the bigger number to be positive so I'm going to start with one and 18 and again I'm going to make the bigger number positive so the smaller number is going to be negative by -1 and 8 teen is Panasonic 17 so that's not it so then I'm going to move on to 2 and 9 make the smaller number negative and 2-9 I mean I'm sorry -2 + 9 is 7 that we're looking for the negative 2 and then I so now I'm going to write my expression in factored form x - 2 + x + 9 again this mr. Four times and then cuz we took the six up here and we multiplied we're going to put it back down here and divide and so I'm going to divide the by 6 and I'm going to divide the 9 by 6 the numbers if they can divide you're just going to divide them if they cannot divide then you're going to simplify the fraction so you can have simplified to 6 - 6 in simplified form is 1/3 you can divide both the numerator and the denominator by 2 so instead of 2 and 6 I have a one here and I have A3 here and said the three is going to move inside so I'm going to have 3x - 1 and then our other fraction 9 / 6 can also simplify we can divide both the numerator and the denominator by 3 so we get three halves so when I simplify this fraction I get three inside the parentheses and to the denominator and we're going to take this too and put it inside of here so that ends up giving us to at last three now that's just the factoring part of the problem so we're going to now bring down the equals 0 that when we factor and solve by factoring we know that each factor could equal 0 so we're going to set you back equal to zero to find the solution so 3x minus 1 equals 0 you're going to add one and / 3 so x equals 1 that's one solution and then we'll set the other Factor equal to zero subtract 3 divided by 2 aynax equals -3/2 sell your soul oceans are -3/2 and positive one third

Video Gallery

Lesson 5-3 Solve by Factoring - when the leading coefficient is not 1

Popular Videos