Error 1 Operator cannot be applied to operands of type string and int

How to solve the problem ?

Error 1 Operator '*' cannot be applied to operands of type 'string' and 'int' 

 int tx = y(0) + y(1) + y(2) + y(3);
            rr1.Text = RadioButton1.Text;
            rr2.Text = RadioButton2.Text;
            rr3.Text = RadioButton3.Text;
            rr4.Text = RadioButton4.Text;
            v1.Text = Convert.ToString(y(0)) + "صوت";
            h1.Text = Convert.ToString(Convert.ToInt32((y(0) / tx) * 100));
            Image1.Width = Convert.ToInt32(h1.Text * 2);
            v2.Text = Convert.ToString(y(1)) + "صوت";
            h2.Text = Convert.ToString(Convert.ToInt32((y(1) / tx) * 100));
            Image2.Width = Convert.ToInt32(h2.Text * 2);
            v3.Text = Convert.ToString(y(2)) + "صوت";
            h3.Text = Convert.ToString(Convert.ToInt32((y(2) / tx) * 100));
            Image3.Width = Convert.ToInt32(h3.Text * 2);
            v4.Text = Convert.ToString(y(3)) + "صوت";
            h4.Text = Convert.ToString(Convert.ToInt32((y(3) / tx) * 100));
            Image4.Width = Convert.ToInt32(h4.Text * 2);
            HttpCookie ck1 = new HttpCookie("vv", "t");
            Response.Cookies.Add(ck1);
            ck1.Expires = DateAndTime.Now.AddDays(20);
        }