Question

How do you find the sum of cube ?

Answer 1

Answer:

$(2x+5)(4x^{2} -10x+25)=0$

Step-by-step explanation:

Given:

The given equation is.

$8x^{3} +125=0$

Find the some of cube.

Solution:

$8x^{3} +125=0$

$2^{3}x^{3} +5^{3}=0$

$(2x)^{3} +5^{3}=0$----------(1)

The sum of the cube formula is given below.

$(a^{3} +b^{3})=(a+b)(a^{2} -ab+b^{2} )$-----------(2)

By comparing equation 1 and equation 2

$a=2x, b=5$

substitute a and b value in equation 2

$((2x)^{3} +5^{3})=(2x+5)((2x)^{2} -(2x)(5)+5^{2})$

$((2x)^{3} +5^{3})=(2x+5)(4x^{2} -(10x)+25)$

$((2x)^{3} +5^{3})=(2x+5)(4x^{2} -10x+25)$

Therefore the sum of the cube $(2x+5)(4x^{2} -10x+25)=0$