#### Answer

$49 = XLIX$

#### Work Step by Step

RECALL:
$L=50
\\X=10
\\V=5
\\I=1$
When a smaller numeral is written before a bigger numeral, the value of the smaller is subtracted to the value of the bigger numeral.
Note that:
$49 = 40+9
\\49 = (50-10) + (10-1)
\\49 = XLIX$