Buddies help me:(
I am confused how to solve this identity:(​

Explanation:

Cubing something means we're multiplying it by itself three times

Something like m^3 means m*m*m

So (a+b)^3 means (a+b)*(a+b)*(a+b)

Let's focus on (a+b)*(a+b) for now. We would use the FOIL rule to find that

(a+b)*(a+b) = a^2 + 2ab + b^2

So we can say

(a+b)*(a+b)*(a+b) = (a+b)(a^2 + 2ab + b^2)

Now let

c = a+b

that way we then have,

(a+b)(a^2 + 2ab + b^2) = c(a^2 + 2ab + b^2)

From here, distribute that 'c' through to each term

c(a^2 + 2ab + b^2)

a^2*c + 2abc + b^2*c

a^2( c ) + 2ab( c ) + b^2( c )

Next, replace c with a+b and apply distribution three more times

a^2( c ) + 2ab( c ) + b^2( c )

a^2( a+b ) + 2ab( a+b ) + b^2( a+b )

a^3 + a^2b + 2a^2b + 2ab^2 + ab^2 + b^3

a^3 + 3a^2b + 3ab^2 + b^3

You could also apply the Binomial Theorem to get the same result. The binomial coefficients can be computed through the combination formula, or through using Pascal's Triangle.

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".

answer: it's d

step-by-step explanation: