Question

here a subtraction problem that has been solved incorrectly for 21-9=11 choose the addition sentence that check this subtraction problem the choices are 21-9=11 29+9=30 what is the correct answer but my answer came to 21+9=30 all it said is change it to a addition problem​

Answer 1

11+ 9 = 20

Explanation:

=> 21-9=11

21 - 9 equals to 11 is actually a wrong answer

So in order to find the subtraction problem that will help us truly know whether the equation is wrong

=> 11+ 9 = 20

OR THE SECOND EQUATION IS

=> 21 - 11 = 10