Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If $a^2 + b^2 + c^2 + 48 = 8(a + b + c)$, then what is the value of \(\sqrt[3]{a^3-b^3+c^3}\) ?

Options:

6

4

3

2

Correct Answer:

4

Explanation:

a+ b2 + c+ 48 = 8(a + b + c)

= a2 - 8a + 16 + b2 - 8b + 16 + c2 - 8c + 16 = 0

= (a - 4)2 + (b - 4)+ (c - 4)2  = 0

When the sum of the squares is 0 then the value of each of them is equal to 0.

So,

 a - 4 = 0

b - 4 = 0

c - 4 = 0

= a = b = c = 4e

Now the value of \(\sqrt[3]{a^3-b^3+c^3}\)  = \(\sqrt[3]{4^3-4^3+4^3}\) = \(\sqrt[3]{64}\)  = 4