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Pearson Algebra 1 Common Core, 2011

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Pearson Algebra 1 Common Core, 2011 View details

8. An Introduction to Equations

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Exercise 45 Page 57

Use mental math to guess the starting value for the table.

8

Practice makes perfect

We want to use a table to solve the given equation.

1/2x-5=-1 In order to choose a good starting point for our table, let's pretend that the equation is 12x=-1. What multiplied by 12 would get us close to -1? 10 would be good, so let's try that in our table. We should also try two digits less and two digits greater, just to be on the safe side.

x	1/2x-5	=
8	1/2( 8)-5	-1
9	1/2( 9)-5	-1/2
10	1/2( 10)-5	0
11	1/2( 11)-5	1/2
12	1/2( 12)-5	1

We can see that x=8 is the solution to our equation.

Subchapter links

Lesson Check p.56

Practice and Problem-Solving Exercises p.56-58

Standardized Test Prep p.58

Mixed Review p.58