Answer
**(ii)** The values are \( p = \frac{5}{4} \) and \( q = \frac{3}{2} \).
**(iii)** The solution to the inequality \( |x+2| \geqslant 3 \) is \( x \leqslant -5 \) or \( x \geqslant 1 \).
Solution
**(ii)** We are given the equation
\[
2p+3iq+\frac{1}{1+i}-(2+i)^2=0.
\]
Assuming \(p\) and \(q\) are real numbers, we begin by simplifying the complex fractions and powers.
1. Compute \((2+i)^2\):
\[
(2+i)^2 = 2^2+2\cdot2\cdot i+i^2 = 4+4i-1=3+4i.
\]
2. Simplify \(\frac{1}{1+i}\) by multiplying the numerator and denominator by the conjugate \(1-i\):
\[
\frac{1}{1+i}=\frac{1}{1+i}\cdot\frac{1-i}{1-i}=\frac{1-i}{(1+i)(1-i)}=\frac{1-i}{1^2-i^2}=\frac{1-i}{1-(-1)}=\frac{1-i}{2}=\frac{1}{2}-\frac{i}{2}.
\]
3. Substitute these results into the original equation:
\[
2p+3iq+\left(\frac{1}{2}-\frac{i}{2}\right)-(3+4i)=0.
\]
Group the real and imaginary parts:
- **Real part:**
\[
2p+\frac{1}{2}-3 =2p-\frac{5}{2}.
\]
- **Imaginary part:**
\[
3iq-\frac{i}{2}-4i=i\left(3q-\frac{1}{2}-4\right)=i\left(3q-\frac{9}{2}\right).
\]
4. For the complex equation to be zero, both the real part and the imaginary part must vanish:
- **Real part:**
\[
2p-\frac{5}{2}=0 \quad\Longrightarrow\quad 2p=\frac{5}{2}\quad\Longrightarrow\quad p=\frac{5}{4}.
\]
- **Imaginary part:**
\[
3q-\frac{9}{2}=0 \quad\Longrightarrow\quad 3q=\frac{9}{2}\quad\Longrightarrow\quad q=\frac{9}{6}=\frac{3}{2}.
\]
Thus,
\[
\boxed{p=\frac{5}{4},\quad q=\frac{3}{2}}.
\]
---
**(iii)** We need to solve the inequality
\[
|x+2|\geqslant 3.
\]
The absolute value inequality \( |x+2|\geqslant 3 \) means that the expression inside the absolute value is either at least 3 or at most \(-3\). This gives us two cases:
1. \( x+2\geqslant 3 \)
\[
x+2\geqslant 3\quad\Longrightarrow\quad x\geqslant 1.
\]
2. \( x+2\leqslant -3 \)
\[
x+2\leqslant -3\quad\Longrightarrow\quad x\leqslant -5.
\]
Hence, the solution is
\[
\boxed{x\leqslant -5\quad\text{or}\quad x\geqslant 1}.
\]
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