diff --git a/assignments/02/02_2.cpp b/assignments/02/02_2.cpp
index 5971bdf..6c1fcc6 100644
--- a/assignments/02/02_2.cpp
+++ b/assignments/02/02_2.cpp
@@ -3,7 +3,7 @@
 
 int check_number(std::string number, double* checked_number) {
     std::size_t pos;
-    *checked_number = std::stoi(number, &pos); // how to properly type check? or is that not necessary?
+    *checked_number = std::stoi(number, &pos); // how to properly type check?
     return 0;
 }
 
@@ -18,17 +18,15 @@ int main(int argc, char *argv[]) {
         std::cout << "Something went wrong. :/" << std::endl;
         return check;
     }
-    double p = b/a;
-    double q = c/a;
+    double d = b*b - 4*a*c;
     
-    double w = (p*p / 4) - q;
-    if (w < 0) {
+    if (d < 0) {
         std::cout << "No real solutions." << std::endl;
         return 0;
     }
     
-    double x_1 = -(p / 2) + sqrt(w);
-    double x_2 = -(p / 2) - sqrt(w);
+    double x_1 = (-b + sqrt(d))/(2*a);
+    double x_2 = (-b - sqrt(d))/(2*a);
     
     if (x_1 == x_2)
         std::cout << "Double zero at x = " << x_1 << std::endl;