Lesson 4: Fractions — Practice Questions

1. 1. What is the lowest common denominator (LCD) for the fractions $\frac{7}{8x^3y}$ and $\frac{2}{12xy^4}$? The LCD is ___.

2. 2. What is the lowest common denominator (LCD) for the expressions $\frac{2}{z+4}$ and $\frac{z}{z-1}$?

   • A. (z+4)(z-1)
   • B. $z^2-4$
   • C. 2z+3
   • D. z+3

3. 3. Find the lowest common denominator (LCD) for $\frac{p}{p^2-9}$ and $\frac{2p}{p^2+3p}$. The LCD is ___.

4. 4. Which expression represents the LCD of $\frac{3}{k^2-4k}$ and $\frac{k}{k^2-16}$?

   • A. k(k-4)(k+4)
   • B. k(k-4)
   • C. (k-4)(k+4)
   • D. $k^2(k-4)(k+4)$

5. 5. What is the LCD for the fractions $\frac{x}{7y}$ and $\frac{3}{y+5}$?

   • A. 7y(y+5)
   • B. 7y + (y+5)
   • C. $7y^2+5$
   • D. y+5

6. 6. What is the lowest common denominator (LCD) needed to add the fractions $\frac{3}{a-5} + \frac{7}{a+2}$?

   • A. $(a-5)(a+2)$
   • B. $10$
   • C. $a-5$
   • D. $a+2$