Combine like terms.
(5x+1)(5x-1)

Apply the distributive property.

5 x ( 5 x ) + 5 x⋅ − 1 + 1 ( 5 x ) + 1 ⋅ − 1 DO THIS THREE TIMES THEN THE ANWER WILL/SHOULD BE 25 x 2 − 1

Step-by-step explanation:

25x^2-1

Step-by-step explanation:

so you have to use the FOIL method which is F: First O: Outer I: Inner L: Last

So for (5X+1)(5X-1) you multiply 5x by 5x

which equals 25x^2

then you multiply 5x by -1 which is -5x

then you multiply 5x and 1 which is 5x

and you subtract 5x by -5x which is 0

finally you multiply 1 and -1 which is -1 and you put it all together which is 25x^2 -1

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".