private void button1_Click(object sender, EventArgs e) { if (Convert.ToDouble(textBox1.Text) == 0) { label6.Text = "Ошибка: a не может быть 0"; return; } else { label6.Text = ""; } linear.SetA(Convert.ToDouble(textBox1.Text)); linear.SetB(Convert.ToDouble(textBox2.Text)); linear.CalculateAnswer(); label3.Text = $"Ответ: x = {linear.GetAnswer()}"; }