Do Now 10/2/09Do Now 10/2/09

Take out HW from last night.Take out HW from last night. Text page 137-139, #32-62 evenText page 137-139, #32-62 even

Copy HW in your planner.Copy HW in your planner. Text page 144-146, #4-40 evenText page 144-146, #4-40 even

In your journal, answer the following questions. How much do you pay In your journal, answer the following questions. How much do you pay (or your parents) a month for your cell phone bill? What is your plan? (or your parents) a month for your cell phone bill? What is your plan? (If you do not have a cell phone estimate the costs). Do you know how (If you do not have a cell phone estimate the costs). Do you know how you are charged per month by your cell phone provider? Explain. you are charged per month by your cell phone provider? Explain.

HomeworkHomework Text page 137-139, #32-62 even Text page 137-139, #32-62 even

32) -4.232) -4.2 34) -8.334) -8.3 36) -636) -6 38) -11.538) -11.5 40) 4240) 42 42) -3542) -35 44) 3544) 35 46) 1/646) 1/6 48) -248) -2 50) 72 = ½ (16)x; 9 cm50) 72 = ½ (16)x; 9 cm

52) 4952) 49 54) 2.5 mm54) 2.5 mm 56) 245 lb56) 245 lb 58) Sally worked 15 58) Sally worked 15

hours in a week and hours in a week and earned $135. How much earned $135. How much did she earn an hour? $9did she earn an hour? $9

60) a. 18ft² b. 6ft.60) a. 18ft² b. 6ft. 62) 47.5 ft²62) 47.5 ft²

ObjectiveObjective SWBAT solve two-step equations using SWBAT solve two-step equations using

algebraalgebra

Did you know your cell phone bill is calculated from a two-step equation?

Equation-Equation-mathematical sentence mathematical sentence

with an equal signwith an equal sign

Like a scale,Like a scale,both sides must be both sides must be EQUALEQUAL in order in order to be balanced.to be balanced.

Solving a Two-Step EquationSolving a Two-Step Equation

How can you get the “unknown” by How can you get the “unknown” by itself?itself?

““Undo” operations by using the Undo” operations by using the INVERSEINVERSE (opposite) operation to both sides of the (opposite) operation to both sides of the

equation.equation.Solving Two-Step EquationsSolving Two-Step Equations

STEP 1- “Undo” addition and/or subtraction.STEP 1- “Undo” addition and/or subtraction.STEP 2- “Undo” multiplication and/or division.STEP 2- “Undo” multiplication and/or division.STEP 3- Solve for the variable.STEP 3- Solve for the variable.STEP 4- Check your work.STEP 4- Check your work.

3x + 5 = -193x + 5 = -19

Solving Two-Step Equations…Solving Two-Step Equations…

3x + 5 = -193x + 5 = -19- 5 5 -5 5

3x = -243x = -24

Isolate the variable! Get ‘x’ by itself.Isolate the variable! Get ‘x’ by itself.

To get the ‘x’ byTo get the ‘x’ by itself first get rid itself first get rid of “adding 5.” of “adding 5.”

Do the opposite.Do the opposite.““Subtract 5.”Subtract 5.”

Whatever you do toWhatever you do toone side of the equationone side of the equationyou must do the other side.you must do the other side.

33 3 3 x = -8x = -8

To get the ‘x’ byTo get the ‘x’ by itself get rid itself get rid of “multiplying by 3.” of “multiplying by 3.”

Do the opposite.Do the opposite.““Divide by 3.”Divide by 3.”

Check Your Work!Check Your Work!

3x + 5 = -193x + 5 = -19x = -8x = -8

3(3(-8-8) + 5 = -19) + 5 = -19

Are both sides equal?Are both sides equal?

““Two-Step”Two-Step”MillionaireMillionaire

HomeworkHomework

Text page 144-146, #4-40 evenText page 144-146, #4-40 even