How do I go about solving this.

We know that angle CBD is a right angle.
We also know that angle ABE is 180°.
Our unknown angle values are angle DBE and angle CBA.
angle CBD minus angle ABE will be 90°.
angle ABC plus angle DBE must equal 90°.
Solving for x:
(x+15)+(x)=90°
(x+15-15)+(x)=90°-15
(x)+(x)=75°
2x=75°
2x/2=75°/2
x=37.5°
Checking the work:
ABC=37.5°+15=52.5°
CBD=90°
DBE=37.5°
In conclusion, ABC plus CBD plus DBE equals 180°
Hope this helped!