really confused on this geometry problem can someone please help.

the sum of the angles is equal to 180, therefore
[tex]\begin{gathered} m\angle A+m\angle B=180 \\ 2x-10+5x+15=180 \\ 7x+5=180 \\ 7x+5-5=180-5 \\ 7x=175 \\ \frac{7x}{7}=\frac{175}{7} \\ x=25 \end{gathered}[/tex]answer:
x = 25