Question: 19. What is the least common denominator (LCD) that could be used to clear the equation of fractions?
$$\frac{2}{5}x + \frac{2}{3} = \frac{7}{4}$$
20. How many terms will have to be multiplied by the least common denominator (LCD)?
21. Rewrite the equation with the fractions cleared.
22. Solve for x.
1. **State the problem:** We need to solve the equation $$\frac{2}{5}x + \frac{2}{3} = \frac{7}{4}$$ by clearing the fractions using the least common denominator (LCD).
2. **Find the LCD:** The denominators are 5, 3, and 4.
The prime factors are:
- 5 is prime
- 3 is prime
- 4 = 2^2
The LCD is the product of the highest powers of all primes:
$$\text{LCD} = 5 \times 3 \times 2^2 = 5 \times 3 \times 4 = 60$$
3. **Number of terms to multiply:** There are 3 terms with denominators: $$\frac{2}{5}x$$, $$\frac{2}{3}$$, and $$\frac{7}{4}$$.
Each term must be multiplied by the LCD to clear fractions.
4. **Multiply each term by the LCD:**
$$60 \times \frac{2}{5}x + 60 \times \frac{2}{3} = 60 \times \frac{7}{4}$$
Calculate each:
$$60 \times \frac{2}{5}x = \cancel{\frac{60}{5}} \times 2x = 12 \times 2x = 24x$$
$$60 \times \frac{2}{3} = \cancel{\frac{60}{3}} \times 2 = 20 \times 2 = 40$$
$$60 \times \frac{7}{4} = \cancel{\frac{60}{4}} \times 7 = 15 \times 7 = 105$$
5. **Rewrite the equation without fractions:**
$$24x + 40 = 105$$
6. **Solve for $$x$$:**
Subtract 40 from both sides:
$$24x + 40 - 40 = 105 - 40$$
$$24x = 65$$
Divide both sides by 24:
$$x = \frac{65}{24}$$
This fraction cannot be simplified further.
**Final answer:** $$x = \frac{65}{24}$$