Number Difference 25F521
1. **State the problem:**
Find all numbers $x$ such that the difference of the number and 3 equals half of the quotient of thrice the number and the sum of the number and two.
2. **Write the equation:**
The difference of a number and 3 is $x - 3$.
The quotient of thrice the number and the sum of the number and two is $\frac{3x}{x+2}$.
Half of this quotient is $\frac{1}{2} \times \frac{3x}{x+2} = \frac{3x}{2(x+2)}$.
So the equation is:
$$x - 3 = \frac{3x}{2(x+2)}$$
3. **Solve the equation:**
Multiply both sides by $2(x+2)$ to clear the denominator:
$$2(x+2)(x - 3) = 3x$$
Expand the left side:
$$2(x^2 - 3x + 2x - 6) = 3x$$
$$2(x^2 - x - 6) = 3x$$
$$2x^2 - 2x - 12 = 3x$$
Bring all terms to one side:
$$2x^2 - 2x - 12 - 3x = 0$$
$$2x^2 - 5x - 12 = 0$$
4. **Use the quadratic formula:**
For $ax^2 + bx + c = 0$, $x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$.
Here, $a=2$, $b=-5$, $c=-12$.
Calculate the discriminant:
$$\Delta = (-5)^2 - 4(2)(-12) = 25 + 96 = 121$$
Calculate the roots:
$$x = \frac{5 \pm \sqrt{121}}{2 \times 2} = \frac{5 \pm 11}{4}$$
So,
$$x_1 = \frac{5 + 11}{4} = \frac{16}{4} = 4$$
$$x_2 = \frac{5 - 11}{4} = \frac{-6}{4} = -\frac{3}{2}$$
5. **Check for restrictions:**
The denominator $x+2$ cannot be zero, so $x \neq -2$. Both solutions are valid.
6. **Final answer:**
The numbers are $\boxed{4}$ and $\boxed{-\frac{3}{2}}$.
This completes the solution using Polya's four-step process.