Addition & Subtraction
x + 2 = 5
x = 3
5x = -10
x = -2
1/5a = 7
a = 35
What is the inverse operation of:
1) Addition?
2) Multiplication?
3) Division?
4) Subtaction?
The inverse of
1) Addition is Subtraction
2) Multiplication is Division
3) Division is Multiplication
4) Subtaction is Addition
A variable represents an unknown value or unknown input.
a + 5 = 2
x = -3
-3x = 0
x = 0
9 = 2/3m
m = 27/2
"the dot"
"the asterick" or "the star"
"parentheses"
We do not use "x" to represent multiplication because we will confuse it with the variable "x"
Give an example of an equation with both a negative sign and a subtraction sign.
Example: -2x - 4 = 5
"negative two x minus four equals five"
x + 7 = -3
x = -10
-2/5x = 8
x = -20
-4/7x = 3
x = -21/4
How you ______ an expression is how you should _______ it in the calculator.
How you say an expression is how you should type it in the calculator.
What is the first step to solve this equation?
16 = -10x
Switch the sides, so that the variable 10x is on the right side and the constant 16 is on the left side.
-15 = x - 6
x = -9
5.6 = 1.4x
x = 4
-11.5x = 34.5
x = -3
How do we say this equation?
-2/3x - 5 = 10.6
____ two _____ three x _____ five _____ 10.6
-2/3x - 5 = 10.6
negative two over three x minus five equals 10.6
Simplify: 8/28
2/7
-27 = c + 27
x = -56
-4.8 = -0.4c
c = 12
-48.6 = -8.1k
"Isolate the variable" means to __________.
1) get the variable by itself.
2) solve for the variable.
3) determine the value of the variable that makes the equation true.
Describe and show 2 mistakes on the board that you or other students can make when solving one-step equations.
Answers vary. Teacher will verify.