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.

the saving company have is: 24  *$1.25 = 30

Step-by-step explanation:

I think your question is missed of key information, allow me to add in and hope it will fit the original one.  Please have a look at the attached photo.

My

We need to caculate the surface areas of

Box 1 = 2lw+2lh+2hw = 2*20*4 + 2*20*6 + 2*6*4 = 448

Box 2 = 2lw+2lh+2hw = 2*15*8 + 2*15*4 + 2*4*8 = 424

So the differences in surface areas of the two boxes is:

448  - 424

= 24  

So the saving company have is: 24  *$1.25 = 30

Hope it will find you well.