Before we begin… Please take out your notebook and get ready to work…. Ok…so far we have simplified and solved 2- step equations… In today’s lesson we will learn how to write 2- step equations… This can have application in the real world…for example…if you wanted to take out a loan…you will need to be able to figure how much and when the loan can be repaid…
10.3 Objective Students will write and solve 2-step equations.
Writing 2-step Equations The key to writing 2 step equations is to know what the words mean… In chapter 1 we look at English words and their meaning in math… Let’s do a quick review of some of those words…
Words that mean Add or Subtract AdditionSubtraction Plus Increased by In all More than Sum Total Minus Subtract Decreased by Less Difference Less than
Words that mean Multiply or Divide MultiplyDivide Times Product Multiplied Each Of Factors Divided Quotient An, in, or per Rate Ratio Separate
Writing 2-step Equations The key or basic concept to writing 2- step equations is to identify the variable first… The clue to identifying the variable are the words…”a number” Let’s look at some examples…
Identify the variable Eight less than three times a number is -23 Thirteen is 7 more than twice a number The quotient of a number and 4, decreased by1, is equal to 5 Fifteen equals three more than six times a number
Example Ok…now that you have identified the variables…lets use that to write the equations Eight less than three times a number is -23 Three times a number is the variable…write it as 3x Less than means to subtract Is means equal to You get the equation 3x – 8 = - 23
Example 13 = 2x + 7 Thirteen is 7 more than twice a number Twice a number is the variable write it as 2x More means to add Thirteen is means = 13 You get the equation
Example Fifteen equals three more than six times a number Six times a number is the variable – write it as 6n More than means to add Fifteen equals means = 15 You get the equation 15 = 6n + 3
Your Turn In the notes section of your notebook write the sentence and then convert it to a 2-step equation 1. The difference between 12 and twice a number is 18 2. Three more than half a number is 15 3. Two more than 1/3 a number is 6
Comments Think about this… Yesterday you learned how to solve 2-step equations Today, you learned how to write them… So naturally…we will take those two simple tasks and add complexity by combining them and having you write and solve 2-step equations…. Make no mistake about it…you will be expected to be able to write and solve 2-step equations!
Summary In the notes section of your notebook summarize the key concepts covered in today’s lesson Today we discussed: Writing 2-step equations What do you do first? What is the clue?
Assignment Text p. 480 # 7 – 18 Reminder This assignment is due tomorrow You do not have to write the word problem Make sure that you translate each word problem into an equation AND solve each equation. You must show how you solved the equations or no credit!