Class notes 9-14 "UNDOing" to solve equations

Undoing an equation means using inverse operations to get back to the variable (mystery number, Who Am I?)
Look at the way an equation was built.  The last operation that built the equation is the first operation to be undone.  In most cases this means using PEMDAS in the other direction.  We use SADMRP to remember this.

Work from outer to inner, towards the grouping symbols.
First, look for Subtractions and Additions to undo. Use addition and subtraction, the inverses.
Next, look for Divisions and Multiplications to undo. Use multiplication and division, the inverses.
Next, look for Exponents to undo.  We use "R" in SADMRP because the inverse of exponentiation is Root (taking the nth root, finding the nth root).
P means it's time to work inside the Parentheses (grouping symbols).

Homework is page 29, items b, d, f.
Be prepared to talk about the steps of UNDOing, similar to the right-to-left arrows and ovals on page 29.