You want to see if music at night and/or naps during the day affect how long your child sleeps at night. Each month, you randomly decide whether your child will get music at night and/or a nap. Then afterwards, you will compare the average number of hours of sleep your child got each month. The factors in this experiment are:
The treatments in this experiment are:

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".

y= -2x+4, have a great day

y-y1=m(x-x1)

y-1=1(x-8)