Answer:
y =14
Step-by-step explanation:
we know that <a = <b since it is an isosceles triangle
<a = <b = 50
the triangle add to 180 degrees
<a + <b + <c =180
50 + 50 + <c = 180
add like terms
100 + <c = 180
subtract 100 from each side
<c = 180-100
<c = 80
<c = 5y+ 10
80 = 5y+10
subtract 10 from each side
80 -10 = 5y+10-10
80-10 = 5y
70 = 5y
divide by 5
70/5 =5y/5
14 = y
