Drexel dragonThe Math ForumDonate to the Math Forum

Ask Dr. Math - Questions and Answers from our Archives
_____________________________________________
Associated Topics || Dr. Math Home || Search Dr. Math
_____________________________________________

Simplify an Expression


Date: 6/15/96 at 19:50:0
From: YWTSE
Subject: Simplify an expression

Simplify  (9a + 2b) - (4a - 3b)


Date: 6/17/96 at 12:2:25
From: Doctor Dave
Subject: Re: Simplify an expression

Recall that a minus times a minus is a plus and a minus times 
a plus is a minus, so

 -(4a-3b) is the same as (-1)(4a-3b) 

and this is the same as (-1)(4a)+(-1)(-3b) 

which equals (-4a) + (3b)
 
So, (9a + 2b) - (4a-3b) = 9a + 2b - 4a + 3b 

If you combine like terms you get

9a - 4a + 2b + 3b = (9-4)a + (2+3)b = 5a + 5b

-Doctor Dave,  The Math Forum
 Check out our web site!
    
Associated Topics:
Middle School Algebra

Search the Dr. Math Library:


Find items containing (put spaces between keywords):
 
Click only once for faster results:

[ Choose "whole words" when searching for a word like age.]

all keywords, in any order at least one, that exact phrase
parts of words whole words

Submit your own question to Dr. Math

[Privacy Policy] [Terms of Use]

_____________________________________
Math Forum Home || Math Library || Quick Reference || Math Forum Search
_____________________________________

Ask Dr. MathTM
© 1994-2013 The Math Forum
http://mathforum.org/dr.math/