Hi Nathan,
The angles of a rhombus add up to 360
and opposite angles are equal
so if you know 2 angles you also know the opposite angles and you can add all 4
X + (opposite of X) + Y + (opposite of Y) = 360
(7x +1) + (7x +1) + (27x + 9) + (27x+9) = 360
68x + 20 = 360
68x = 340
x = 5
so
X = 7x +1 = 7(5) +1 = 36
Y = 27x + 9 = 27(5) + 9 = 144
Hope this helps.