# Do Now 10/22/ = 10 = ? Copy HW in your planner.

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Do Now 10/22/13 + 7 = 10 = ? Copy HW in your planner.
Text p. 74, #1-3, 8-13, 38, 39, & 41 In your journal, describe the PROCESS (steps you would take) to solve the following question. Then solve. What is this an example of? + 7 = 10 = ?

Objective SWBAT solve equations using addition and subtraction

Section 2-5 “Solving Equations Using Addition & Subtraction”
mathematical sentence formed by placing an “=” between two expressions y – 8 = 12 22 = 14 + z 5 ÷ x = 30 11a = 121

Equation x + 7 = 10 Left side Right side ‘x’ has to be 3 in order to make the equation balanced. Like a scale, the left side and right side must be the same in order to be balanced!

How can you get the “unknown” by itself?
m + 24 = -18 “Undo” the operation by using the INVERSE (opposite) operation to both sides of the equation.

Isolate the variable! Get ‘m’ by itself. m + 24 = -18 To get the ‘m’ by itself get rid of “adding 24.” –24 – 24 Do the opposite. “Subtract 24.” m = -42 Whatever you do to one side of the equation you must do the other side. -18 – 24 -18 + (-24) “opp-opp” -42

m = -42 m + 24 = -18 (-42) + 24 = -18 -18 = -18 Check Your Work!
-18 = -18 Are both sides equal?

Try It Out 1). (6) + 7 = 13 1). x + 7 = 13 2). -7 = 9 + (-16)
1). (6) + 7 = 13 2). -7 = 9 + (-16) 3). -3 = (-10) + 7 4).(-9) + 40 = 31 1). x + 7 = 13 2). -7 = 9 + h 3). -3 = x + 7 4). f = 31

Solving Subtraction Equations…
Isolate the variable! Get ‘y’ by itself. -13 = y –15 To get the ‘y’ by itself get rid of “subtracting 15.” +15 +15 Do the opposite. “Add 15.” 2 = y Whatever you do to one side of the equation you must do the other side.

2 = y -13 = y – 15 -13 = (2) – 15 -13 = -13 Check Your Work!
Are both sides equal?

Try It Out 1). (4) - 7 = -3 1). t - 7 = -3 2). 6 = (3) – (-3)
3). 40 = (61) – 21 4). -15 = (-8) - 7 1). t - 7 = -3 2). 6 = x – (-3) 3). 40 = r – 21 4) = p - 7

24 Homework Text p. 74, #1-3, 8-13, 38, 39, & 41

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