Name that Operation
In the expression 3(x + 2), what operation is being shown between the 3 and the parentheses?
Multiplication
What's the inverse of addition?
Subtraction
x + 6 = 14
8
12 ÷ 4 = 3 — rewrite as a fraction.
12/4 = 3
In 3x + 7 = 22, what's the first move — add/subtract or multiply/divide?
Subtract 7
Rewrite 18 ÷ 3 as a fraction.
18/3
What's the inverse of multiplication?
Division
x − 5 = 12
17
x/6 = 5 — rewrite using ÷ instead of a fraction bar, then solve.
x ÷ 6 = 5; x = 30
In (x/5) + 2 = 9, what's the first move?
Subtract 2
n 5x, where's the multiplication symbol?
To undo "+ −9," what do you do?
x/2 + 7 = 10
6
4 · x + 1 = 9 — is the dot the same as ×? Solve.
Yes, x = 2
In 2x − 6 = 10, what operation undoes the "− 6," and is it first or second?
Add 6, done first
Is x/7 asking you to multiply or divide?
Divide
To undo "÷ -4," what do you do?
Multiply by -4
3x + 5 = −4
-3
−(x/3) = 5 — solve, being careful with the negative.
-15
Why do you handle the +/− step before the ×/÷ step when solving?
Reverse PEMDAS
List two ways to write "n divided by 8."
n ÷ 8, n/8
In solving an equation, why do inverse operations have to be done to both sides?
To keep the equation balanced
x/4 − 2 = 5
28
2(x) − 3 = 7 — does the parentheses mean multiply or something else here? Solve.
Multiply, x=5
6 = 2x − 4 — solve it, and explain why order still matters even though the equation is "backwards."
X = 5, The same steps apply no matter where the variable is located.