Since <em>l</em> and <em>m</em> are parallel, the unlabeled angle adjacent to the 63° one also has measure (7<em>x</em> - 31)° (it's a pair of alternating interior angles).
Then the three angles nearest line <em>m</em> are supplementary so that
(7<em>x</em> - 31)° + 63° + (5<em>x</em> - 8)° = 180°
Solve for <em>x</em> :
(7<em>x</em> - 31) + 63 + (5<em>x</em> - 8) = 180
12<em>x</em> + 24 = 180
12<em>x</em> = 156
<em>x</em> = 13
The bottom-most angle labeled with measure (4<em>y</em> + 27)° is supplementary to the angle directly adjacent to it, so this unlabeled angle has measure 180° - (4<em>y</em> + 27)° = (153 - 4<em>y</em>)°. The interior angles of any triangle have measures that sum to 180°, so we have
(7<em>x</em> - 31)° + 63° + (153 - 4<em>y</em>)° = 180°
We know that <em>x</em> = 13, so 7<em>x</em> - 31 = 60. Then this simplifies to
123° + (153 - 4<em>y</em>)° = 180°
Solve for <em>y</em> :
123 + (153 - 4<em>y</em>) = 180
276 - 4<em>y</em> = 180
96 = 4<em>y</em>
<em>y</em> = 24
