Question

If (a-b)=4,find the value of a3-b3-12ab

Answer 1

Answer:

People find some difficulties in algebra's question.

For this they have to memorise the basic formula of alegbra on finger tips and make a list of them.

Come to this question :-

We need formula's to solve this query, mentioned below for different different approaches, we require different formula. While using Formula's, reduces complexity in solving alegbra's query.

1.) a^3 + b^3 = (a+b)(a^2 -ab + b^2),

2.) (a+b)^3 = a^3 + b^3 + 3ab(a+b),

3.) (a+b)^2 = a^2 + b^2 + 2ab,

Now,

By using Second formula as mentioned above:-

Step 1 :- Given, a+b = 4.

Step 2 :- From the query, we can easily see that the variables contain power of 3, we can use the second formula as described above

-> (a+b)^3 = a^3 + b^3 + 3ab(a+b), given a+b =4,

-> 4^3 = a^3 + b^3 + 3ab(4),

-> 64 = a^3 + b ^3 + 12ab.

Step 3 :- Hence the value is 64,

Now by using first formula as mentioned above :-

Step 1 :- Looking to the question we have to find the value of

a^3 + b^3 + 12ab,

Now, Take a^3 + b^3 from the query, and using the formula of

-> a^3 +b^3 +12ab = (a+b)(a^2 - ab + b^2) +12ab,

-> given a+b =4, put the value in RHS,

-> 4(a^2 -ab + b^2) + 12ab,

-> 4a^2 - 4ab + 4b^2 +12ab ,

-> 4a^2 +8ab +4b^2,

Now taking 4 as common from the equation,

-> 4(a^2 + 2ab + b^2),———equation(1)

Using this in equation (1)->

(a+b)^2 = a^2 + 2ab + b^2, we get

-> 4 ((a+b)^2),

Now given a+b =4,

So 4(4)^2,

Ans is :- 64,

By using formula we can easily calculate the value of equation..

Step-by-step explanation:

Answer 2

Answer:

this is the correct answer for the question