1. **State the problem:** We are given two numbers $A$ and $B$ such that their sum is 28, i.e.,
$$A + B = 28$$
We are also given that half of $A$ plus one-fourth of $B$ equals -2, i.e.,
$$\frac{1}{2}A + \frac{1}{4}B = -2$$
2. **Write down the system of equations:**
$$\begin{cases} A + B = 28 \\ \frac{1}{2}A + \frac{1}{4}B = -2 \end{cases}$$
3. **Solve the system:**
From the first equation, express $B$ in terms of $A$:
$$B = 28 - A$$
4. Substitute $B$ into the second equation:
$$\frac{1}{2}A + \frac{1}{4}(28 - A) = -2$$
5. Simplify the equation:
$$\frac{1}{2}A + 7 - \frac{1}{4}A = -2$$
6. Combine like terms:
$$\left(\frac{1}{2} - \frac{1}{4}\right)A + 7 = -2$$
$$\frac{1}{4}A + 7 = -2$$
7. Subtract 7 from both sides:
$$\frac{1}{4}A = -2 - 7$$
$$\frac{1}{4}A = -9$$
8. Multiply both sides by 4 to solve for $A$:
$$\cancel{4} \times \frac{1}{\cancel{4}}A = -9 \times 4$$
$$A = -36$$
9. Substitute $A = -36$ back into $B = 28 - A$:
$$B = 28 - (-36)$$
$$B = 28 + 36$$
$$B = 64$$
**Final answer:**
$$A = -36, \quad B = 64$$
Sum Two Numbers 646C21
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