Find the mistake made in the steps to solve the equation below.
61 - 1 = -21 + 9
81 - 1 = 9
80 = 10
1. Addition property of
equality
2. Addition property of equality
3. Division property of equality
to
I
CHA
4. Simplification
OA. The justification for step 2 is incorrect and should be the subtraction property of equality.
OB. Step 3 is incorrect and should be r = 100
OC. Step 2 is incorrect and should be r = 8.
OD. The justification for step 3 is incorrect and should be the multiplication property of equality,