Question

simplify. (2x+5)cube - (2x-5) cube​

Answer 1

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

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

$= 4 {x}^{2} + 25 + 60 {x}^{2} + 150x - 4 {x}^{2} + 25 + 60 {x}^{2} - 150x$

$= 50 +120 {x}^{2}$

$= 10(5 + 12 {x}^{2} )$