Answer:
y=14
Step-by-step explanation:
Since this is an isosceles triangle due to opposite sides being congruent, the base angles would also be congruent.
plug in 25 in 2x and you would get 50°
Since the sum of a triangle is 180° you could set up an equation 
Then, add 50+50=100+10=110
then you would then have 
subtract 110 from 180, leaving you with 70

then divide and you would get 14
Check:
5(14)+10+50+50= 180