Literal Equations

Literal Equations

Literal Equations

Equations that contain two or more variables. In this lesson we will learn to rearrange formulas.

A. How can we solve :

 $4x\ \ =\ \ 16$  

What is the reason for dividing?

•  $4x$  is multiplication

• The inverse of multiplication is division.

• So to undo multiplication we divide.

• So by rearranging we isolated the variable and "x" was found

 $A\ =\ l\ \times\ w$  

• The operation is multiplication

• The inverse is division

•  $w\ =\ \frac{A}{l}$  
  
  

 $V\ =\ l\ x\ w\ x\ h$  

• The operation is multiplication

• The inverse is division

•  $h\ =\ \frac{V}{l\ x\ w}$  

Multiple Choice

 $B\ =\ a\ +\ c$  

Solve for "a". What is the inverse operation to be used to undo the equation?

• addition

• multiplication

• subtraction

• division

Multiple Choice

 $\ D\ =\ rt$  

Solve for "t"

•  $t=\ \frac{D}{r}$  

•  $t=\ D\ -\ r$   $t=\ \frac{t}{D}$  

•  $t=\ D+\ r$  

Formulas with more than one operation

•  $y\ =\ mx\ +\ b\ ;\ solve\ for\ "x"$  

• What are the operations in the formula?

• multiplication and addition

• What are the inverse operations?
  

• division and subtraction

 $y\ =\ mx\ +\ b\ ;\ solve\ for\ "x"$  

• 1st subtract "b"            $y\ -\ b\ =mx$  

• 2nd divide by "m"         $\frac{\left(y\ -\ b\right)}{m}\ =x$  

Multiple Choice

 $y=\ mx\ +b;\ solve\ for\ "m"\ \$  

What is the first step?

• add

• subtract

• multiplication

• division

Multiple Choice

 $y\ =\ mx\ +\ b;\ solve\ for\ b$  

•  $y-mx\ =\ b$  

•  $y+mx\ =\ b$  

•  $\frac{y}{mx\ }=\ b$  

•  $y\ +\ mx\ =\ -b$  

Multiple Choice

 $5x\ -y\ =\ 16$ solve for "y" 

•  $-y\ =16\ +\ 5x$  

•  $y=-5x\ +\ 16$  

•  $y\ =\ \frac{16}{5x}$  

•  $y=\frac{5x}{16}$  

Poll

What is your comfort level of rearranging formulas (literal equations)?

• 😊

• 🤔

• 😒

• 😢