Gia has 60 meters of fence. She wants to mark off a square area in the yard for her
dog. What will be the side length of the
square if she uses all of the fence?
The side length will be
meters.

15

Step-by-step explanation:

A square has 4 sides, so you can do 60 divided by 4 to find how many meters on each side.

60 / 4 = 15 meters for the side length

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".