a)

Zauważmy, że:

$1551=\underset{\text{M}}{\underbrace{1000}}+\underset{\text{D}}{\underbrace{500}}+\underset{\text{L}}{\underbrace{50}}+\underset{\text{I}}{\underbrace{1}}$

Zatem:

$1551=\text{MDLI}$

---

b)

Zauważmy, że:

$1632=\underset{\text{M}}{\underbrace{1000}}+\underset{\text{DC}}{\underbrace{\left(500+100\right)}}+\underset{\text{XXX}}{\underbrace{\left(10+10+10\right)}}+\underset{\text{II}}{\underbrace{\left(1+1\right)}}$

Zatem:

$1632=\text{MDCXXXII}$

---

c)

Zauważmy, że:

$1706=\underset{\text{M}}{\underbrace{1000}}+\underset{\text{DCC}}{\underbrace{\left(500+100+100\right)}}+\underset{\text{VI}}{\underbrace{\left(5+1\right)}}$

Zatem:

$1706=\text{MDCCVI}$

---

d)

Zauważmy, że:

$2008=\underset{\text{MM}}{\underbrace{\left(1000+1000\right)}}+\underset{\text{VIII}}{\underbrace{\left(5+1+1+1\right)}}$

Zatem:

$2008=\text{MMVIII}$

---

e)

Zauważmy, że:

$191=\underset{\text{C}}{\underbrace{100}}+\underset{\text{XC}}{\underbrace{\left(100-10\right)}}+\underset{\text{I}}{\underbrace{1}}$

Zatem:

$191=\text{CXCI}$

---

f)

Zauważmy, że:

$249=\underset{\text{CC}}{\underbrace{\left(100+100\right)}}+\underset{\text{XL}}{\underbrace{\left(50-10\right)}}+\underset{\text{IX}}{\underbrace{\left(10-1\right)}}$

Zatem:

$249=\text{CCXLIX}$

---

g)

Zauważmy, że:

$1049=\underset{\text{M}}{\underbrace{1000}}+\underset{\text{XL}}{\underbrace{\left(50-10\right)}}+\underset{\text{IX}}{\underbrace{\left(10-1\right)}}$

Zatem:

$1049=\text{MXLIX}$

---

h)

Zauważmy, że:

$619=\underset{\text{DC}}{\underbrace{\left(500+100\right)}}+\underset{\text{X}}{\underbrace{10}}+\underset{\text{IX}}{\underbrace{\left(10-1\right)}}$

Zatem:

$619=\text{DCXIX}$

---

i)

Zauważmy, że:

$99=\underset{\text{XC}}{\underbrace{\left(100-10\right)}}+\underset{\text{IX}}{\underbrace{\left(10-1\right)}}$

Zatem:

$99=\text{XCIX}$

---

j)

Zauważmy, że:

$499=\underset{\text{CD}}{\underbrace{\left(500-100\right)}}+\underset{\text{XC}}{\underbrace{\left(100-10\right)}}+\underset{\text{IX}}{\underbrace{\left(10-1\right)}}$

Zatem:

$499=\text{CDXCIX}$

---

k)

Zauważmy, że:

$999=\underset{\text{900}}{\underbrace{\left(1000-100\right)}}+\underset{\text{90}}{\underbrace{\left(100-10\right)}}+\underset{\text{9}}{\underbrace{\left(10-1\right)}}$

Zatem:

$999=\text{CMXCIX}$

---

l)

Zauważmy, że:

$1499=\underset{\text{M}}{\underbrace{1000}}+\underset{\text{CD}}{\underbrace{\left(500-100\right)}}+\underset{\text{XC}}{\underbrace{\left(100-10\right)}}+\underset{\text{IX}}{\underbrace{\left(10-1\right)}}$

Zatem:

$1499=\text{MCDXCIX}$