To find <ABC, the first thing you would need to do is to find angle DBA and the value of x
As <DBE is a right angle, <DBE is on the same straight line as well,meaning that it would be 90° , a right angle as well.
It also mean that the total sum of the angles unknown would be 90°
To find x,we need to set up an equation:
(2x+14)+ (x+7) = 90
3x+21 = 90
3x = 69
x = 23
Thus,<ABC would be
(23)+7
=30°
Hope it helps!