fix reducer sign error

src/reducer.c

@@ -21,7 +21,8 @@ static double get_all_terms_with_exponent(s_term *terms, int exponent)
         // sign
         sign = 1;
         if (terms[i].position == TERM_RIGHT)
-            sign = terms[i].sign == TERM_PLUS ? -1 : 1;
+            sign = -1;
+        // sign = terms[i].sign == TERM_PLUS ? -1 : 1;
 
         // add coefficients
         coefficient += terms[i].coefficient * sign;

src/solver.c

@@ -14,7 +14,7 @@ static void solve_degree_1(s_solution_degree_1 *solution, double a, double b)
     solution->a = a;
     solution->b = b;
 
-    solution->solution = positiv_zero(-b / a); // -b / a
+    solution->solution = positiv_zero(-b / a);
 }
 
 static void solve_degree_2(s_solution_degree_2 *solution, double a, double b, double c)