Dividing Rational Algebraic Expressions

Dividing Rational Algebraic Expressions

Sir Ace

Multiple Choice

What is the reciprocal of  $\frac{2}{5}$  ?

•  $\frac{2}{5}$  

•  $\frac{5}{2}$  

• 2

• 5

Multiple Choice

What is the reciprocal of   $\frac{1}{3x}$  ?

• 3x

•  $\frac{1}{3x}$  

• 1

•  $\frac{1}{3}$  

Fill in the Blank

What is the reciprocal of 2x?

What are the words similar to reciprocal?

• reverse

• flip

• switch

How do we divide fractions?

• COPY the 1st fraction

• CHANGE division to multiplication

• FLIP the second fraction

• MULTILPLY

Multiple Choice

 $\frac{3}{4}\div\frac{2}{5}$  

•  $\frac{6}{20}$  

•  $\frac{8}{15}$  

•  $\frac{20}{6}$  

•  $\frac{15}{8}$  

Multiple Choice

 $\frac{3}{16}\div\frac{3}{4}$  

•  $\frac{1}{4}$  

• 4

•  $\frac{9}{64}$  

•  $\frac{12}{48}$  

USE CROSS - CANCELLATION in multiplying fractions

Dividing Rational Algebraic expressions are just the same with dividing fractions.

COPY the 1st fraction

CHANGE division to multiplication

FLIP the 2nd fraction

FACTOR the numerator and denominator

CANCEL common factors

MULTIPLY the remaining factors

EXAMPLE NO. 1

Step 1: Copy, Change and Flip

Step 2: Factor the numerator and denominator

Step 3: Cancel Common factors

Step 4: Multiply the remaining factors

EXAMPLE NO. 2

Step 1: Copy, Change and Flip

Step 2: Factor the numerator and denominator

Step 3: Cancel Common factors

Step 4: Multiply the remaining factors

Multiple Choice

 $\frac{1}{x}\div\frac{2}{x}$  

•  $\frac{2}{x^2}$  

•  $\frac{1}{2}$  

•  $\frac{x}{2}$  

•  $\frac{x}{2x}$  

SOLUTION

Multiple Choice

 $\frac{12x^2}{4yz}\div\frac{3x^2}{9yz}$  

•  $3$  

•  $9$  

•  $\frac{9}{yz}$  

•  $\frac{3}{yz}$  

SOLUTION

Multiple Choice

 $\frac{x^2+x-2}{x-1}\div\frac{x^2+5x+6}{x^2}$  

•  $x^2$  

•  $x+3$  

•  $\frac{x^2}{x+3}$  

•  $\frac{x^2}{x+2}$  

SOLUTION