Solving for a Variable in Several Places in the Equation
_What do you do when you have an equation such as:
2x -3(x + 5) - 4 = 39x - 2(3x -1)?
It is not as complicated as it looks, in fact, you have done this already!
Treat each side of the equation as an expression (no equal sign) and combine your like terms. After that, solve the equation just like you have when there is a variable on both sides of the equal sign.
2x -3(x + 5) - 4 = 39x - 2(3x -1)
distribute 2x -3x -15 = 39x - 6x +2
combine like terms -x - 15 = 33x + 2
addition +15 +15
- x = 33x + 17
subtraction -33x -33x
-34x = 17
division -34 -34
x = - 1/2
PRACTICE
Here is a good tutorial with practice problems to try: http://cnx.org/content/m18033/latest/ Once again it starts with a quick review of solving simpler equations and then moves on to more complex ones. If you want to jump right in to solving the more complex equations, try: http://cstl.syr.edu/fipse/algebra/unit3/steps.htm
ASSESS
Do this assessment of your new skills: http://www.mathsnet.net/algebra/balance.html. It is Swedish, so ":" means divide. How did you do? Post it in the Interactive Assessment forum below.
2x -3(x + 5) - 4 = 39x - 2(3x -1)?
It is not as complicated as it looks, in fact, you have done this already!
Treat each side of the equation as an expression (no equal sign) and combine your like terms. After that, solve the equation just like you have when there is a variable on both sides of the equal sign.
2x -3(x + 5) - 4 = 39x - 2(3x -1)
distribute 2x -3x -15 = 39x - 6x +2
combine like terms -x - 15 = 33x + 2
addition +15 +15
- x = 33x + 17
subtraction -33x -33x
-34x = 17
division -34 -34
x = - 1/2
PRACTICE
Here is a good tutorial with practice problems to try: http://cnx.org/content/m18033/latest/ Once again it starts with a quick review of solving simpler equations and then moves on to more complex ones. If you want to jump right in to solving the more complex equations, try: http://cstl.syr.edu/fipse/algebra/unit3/steps.htm
ASSESS
Do this assessment of your new skills: http://www.mathsnet.net/algebra/balance.html. It is Swedish, so ":" means divide. How did you do? Post it in the Interactive Assessment forum below.