ASAP pls Missing Statement:
[ Select ]
Angle ACD is congruent to Angle BCD
Angle ADC and Angle BCD are Right Angles
Angle ADC is congruent to Angle BDC
Segment AD is congruent to Segment BD

Missing Reason:
[ Select ]
Angle Bisector creates Congruent Angles
Isosceles Triangle Theorem
Midpoint creates Congruent Segments
Segment bisector creates Congruent Segments
Definition of Perpendicular Lines

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".