Cleaned up extra radio button labels

Contrib/Westmont/ActiveCalculus/Preview_2_6/preview_2_6_abcd.pg

@@ -35,7 +35,7 @@ $mc1 = RadioButtons(
 "\(p(x)=1\)",
 "\(p(x)=0\)"],
 "\(p(x)=x\)",
-    labels => ["x", "9x+5", "5x+9", "1", "0"] );
+    );
 
 $mc2 = RadioButtons(
     [
@@ -45,20 +45,20 @@ $mc2 = RadioButtons(
 "\(r(y)=1\)",
 "\(r(y)=0\)"],
 "\(r(y)=y\)",
-    labels => ["y", "9y+5", "5y+9", "1", "0"] );
+   );
 
 TEXT(beginproblem());
 Context()->texStrings;
 BEGIN_TEXT
 The equation \(y = \frac{9}{5}(x - 32)\)  relates a temperature given in \(x\)
 degrees Fahrenheit to the corresponding temperature \(y\) measured in degrees Celcius. $PAR
 
-Solve the equation \(y = \frac{9}{5} (x - 32)\) for \(x\) to write \(x\) 
+Solve the equation \(y = \frac{9}{5} (x - 32)\) for \(x\) to write \(x\)
 (Fahrenheit temperature) in terms
 of \(y\) (Celcius temperature). $BR
 \(x = \) \{ ans_rule(20) \}. $PAR
 
-Let \(C(x) = \frac{9}{5} (x - 32)\) 
+Let \(C(x) = \frac{9}{5} (x - 32)\)
 be the function that takes a Fahrenheit temperature as input
 and produces the Celcius temperature as output. In addition, let \(F(y)\) be the
 function that converts a temperature given in \(y\) degrees Celcius to the temperature
@@ -72,7 +72,7 @@ as possible. What do you observe? $BR
 \{ $mc1->buttons() \}
 $PAR
 Now, let \(r(y) = C(F(y))\). Use the formulas for
-\(F\) and \(C\) to determine an expression for \(r(y)\) 
+\(F\) and \(C\) to determine an expression for \(r(y)\)
 and simplify this expression as much
 as possible. What do you observe? $BR
 \{ $mc2->buttons() \}
@@ -97,4 +97,3 @@ END_SOLUTION
 Context()->normalStrings;
 
 ENDDOCUMENT();
-