Arectangular lot whose perimeter is 380 ft is fenced along three sides. an expensive fencing along the lot's length cost $ 25 per foot. an inexpensive fencing along the two side widths costs only $ 5 per foot. the total cost of the fencing along the three sides comes to $ 3625. what are the lot's dimensions?

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".