PDF chapter test TRY NOW

Answer variants:
Results in \(30ab\)
Cannot cancel \(15\) from the expression
Cannot cancel \(7a\) from the expression
Results in \(15(a+b)\)
Spot the suitable error reason.
 
1. 7a+1515=7a -
 
Correct the error and conclude the answer.
 
2. 15a+15b -