4Before 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…
510.3 ObjectiveStudents will write and solve 2-step equations.
6Writing 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…
7Words that mean Add or Subtract Addition SubtractionPlusMinusIncreased byLessSubtractSumIn allLess thanMore thanDecreased byTotalDifference
8Words that mean Multiply or Divide Multiply DivideDividedTimesRateMultipliedProductQuotientEachAn, in, or perOfRatioFactorsSeparate
9Writing 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…
10Identify the variable Eight less than three times a number is -23 Thirteen is 7 more than twice a numberThe quotient of a number and 4, decreased by1, is equal to 5Fifteen equals three more than six times a number
11Example Eight less than three times a number is -23 Ok…now that you have identified the variables…lets use that to write the equationsEight less than three times a number is -23Three times a number is the variable…write it as 3xLess than means to subtractIs means equal toYou get the equation3x – 8 = - 23
12Example Thirteen is 7 more than twice a number 13 = 2x + 7 Twice a number is the variable write it as 2xMore means to addThirteen is means = 13You get the equation13 = 2x + 7
13Example Fifteen equals three more than six times a number 15 = 6n + 3 Six times a number is the variable – write it as 6nMore than means to addFifteen equals means = 15You get the equation15 = 6n + 3
14Your TurnIn the notes section of your notebook write the sentence and then convert it to a 2-step equationThe difference between 12 and twice a number is 18Three more than half a number is 15Two more than 1/3 a number is 6
15Comments Think about this… Yesterday you learned how to solve 2-step equationsToday, 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!
16SummaryIn the notes section of your notebook summarize the key concepts covered in today’s lessonToday we discussed:Writing 2-step equationsWhat do you do first?What is the clue?
17Assignment Text p. 480 # 7 – 18 Reminder This assignment is due tomorrowYou do not have to write the word problemMake 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!