adding and subtracting values in textbox

Question

textBox10.Text = (Decimal.Parse(textBox8.Text)) - (((Decimal.Parse(textBox6.Text)) *(Decimal.Parse(textBox9.Text).ToString())));


guys i wanted to multiply textbox6 and textbox9 and subtract it to textbox8 i have coded it as above and i am getting error so please help me in this code thanks in advance