Addition and Subtraction of Rational Expression

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• $\frac{4a-2b+6}{4ab}$

• $\frac{2a-b+3}{2ab}$

• $\frac{12a-4b}{8ab}$

 $\frac{4}{x-3}+\frac{7}{x+4}$  

•  $\frac{3x+37}{\left(x-3\left(x+4\right)\right)}$  

•  $\frac{3x+5}{\left(x-4\right)\left(x+3\right)}$  

•  $\frac{11x-5}{\left(x-3\right)\left(x+4\right)}$  

 $\frac{3m+4}{m+1}-\frac{m+2}{m-1}$  

•  $\frac{2m^3-2m+6}{m^2-1}$  

•  $\frac{4m^2-2m+6}{m^2-1}$  

•  $\frac{2m^2-2m-6}{m^2-1}$  

Find the least common denominator of the expression

 $\frac{5}{4xy}+\frac{7}{8x}$  

• 4xy

• 12x

• 8xy

 $\frac{x-1}{15x+12}+\frac{8-2x}{15x+12}$  

•  $\frac{3x+7}{15x+12}$  

•  $\frac{-x+7}{15x+12}$  

•  $\frac{-x-1}{15x+12}$  

 $\frac{16}{7x}+\frac{5}{7x}$  

•  $\frac{x}{3}$  

•  $\frac{3}{x}$  

• 3x

 $\frac{1}{4x}-\frac{3}{5x^2}$  

•  $\frac{5x-12}{20x^2}$  

•  $\frac{3x+12}{20x}$  

•  $\frac{5x+12}{20x^3}$  

Find the LCD of

 $\frac{3x}{x^2-25}-\frac{2}{x-5}$  

•  $\left(x-5\right)\left(x-5\right)$  

•  $\left(x+5\right)\left(x+5\right)$  

•  $\left(x-5\right)\left(x+5\right)$  

What must be the first step in adding and subtracting dissimilar rational expressions ?

• Combine like terms in the numerators.

• Determine a Least Common Denominator.

• Factor all of the numerators and all of the denominators.