Question

expand the following 5 x + 3 whole cube ​

Answer 1

${(x + y)}^{3} = {x}^{3} + {y}^{3} + 3 {x}^{2} y + 3 {y}^{2} x$

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

$= 125 {x}^{3} + 27 + 225 {x}^{2} + 135x$

Answer 2

(5x +3)³

(a+b)³ = (a+b) (a² + b² - ab)

so

(5x + 3) ({5x}² + {3}² - 5x . 3)

so

(5x +3 ) ( 25x² + 9 -15x )

75x³ + 45x -75x² + 75x² + 27 - 45x

so

45x nd 75x² will be cancelled out

Therefore

75x³ + 27 is required answer

Hope it helped you