What is the value of y? enter your answer in the box. y = an isosceles triangle with vertices labeled a, b, and c. side b c is the base. sides a b and a c are equal. sides a b and a c are labeled with single tick marks. angle a is labeled as left parenthesis 4 y plus 10 right parenthesis degrees, angle b is labeled as 75 degrees, and angle c is labeled as left parenthesis 3 x right parenthesis degrees.