Factor and Multiply to Check
Date: 5/21/96 at 16:0:14 From: Beverly Jenkins Subject: Factoring Dr. Math, I am in Algebra 1. Here's are the directions: Factor. Check by multiplying the factors. If the polynomial is not factorable, write "prime." The first problem is x to the second power plus 6x plus 5. Help if you can!
Date: 7/2/96 at 16:11:36 From: Doctor Leigh Subject: Re: Factoring Beverly, Your teacher probably wants you to see if you can use one of a couple of methods to factor an equation. One possible method for factoring equations is done by finding a common factor and then factoring it out. Since there are no common factors in x^2 + 6x + 5, we need to try something else. Another possible method is called the difference of two perfect squares. If an equation consists of two perfect squares with a subtraction sign between them, the equation can be factored using this method. However, since this equation is not the difference of two perfect squares we should try another way. A third possible solution is using reverse FOIL. This is used if you have an x squared term along with an x term and then a constant (no x). You try to find two numbers that, when added, add up to the middle number, and when multiplied are the constant. Are there any such numbers that add up to be 6 and multiply to be five? Yes! One times five is five, and one plus five is six. So, our factors are (x+1)(x+5). Multiply these out to check. Thanks for your question. I hope I was able to help. -Dr. Leigh Ann The Math Forum Check out our Web site: http://mathforum.org/dr.math/
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994-2013 The Math Forum