Building an equation from an unknown number ("me", "what number am I?") uses the words closest to the number to suggest the first operations and grouping. Each word phrase adds another operation or grouping. Finally, you translate "am I" or "I am" into an equal sign.
Solving an equation for an unknown number looks at the operation farthest away from the number so you can undo it. Remember that when you undo something, such as when typing at a computer, you affect the last thing you did. When you undo in math, you affect the last operation used to build the equation.
To undo a math operation, you use its inverse. Multiplication and division are inverses. Addition and subtraction are inverses. If the equation's last piece was adding 3 (" + 3 ") to undo it so you can make the equation simpler you should subtract 3 (" - 3") from both sides.
To evaluate an expression or to build an equation, you use the order of operations PEMDAS.
To solve an equation, you use the order of undoing operations SADMRP.
We use R instead of E because Root is the inverse of Exponent. If raising to a power/raising to an exponent was used to build an equation, tkaing the root/finding the root is used to undo the equation
No comments:
Post a Comment