Transcript 4-2 Using Number Sense to Solve Equations and 4

4-2 Using Number Sense to
Solve Equations
and
4-3 Solving Equations by Adding
and Subtracting
Equation- a math sentence with an equal
sign.
Open Sentence- an equation with one or
more variables.
Solution of an Equation- a value for a
variable that makes an equation true.
Substitution
Find the solution of 12m = 108 by
substituting 4, 7, and 9.
12(4) = 108
48 = 108
NO
12(7) = 108
84 = 108
NO
The solution is 9.
12(9) = 108
108 = 108
YES
Inverse Operations- operations that undo
each other.
Addition and Subtraction
Multiplication and Division
When Solving Equations…
1.) Identify the variable.
2.) Isolate the variable.
3.) Get rid of whatever numbers are on the
same side as the variable by using inverse
operations.
4.) What you do to one side of the equal
sign, you must do to the other.
5.) Do the math.
Solving Equations by Adding
Solving Equations by Subtracting
Practice
Solve.
1.) x - 6 = -55
2. ) 34 = g + 25
3.) d + 261.9 = -48
4.) 62.5 + t = -77