Question

find the value of (28)^3-(48)^3+(50)^3 by identity

Answer 1

$(28)^3-(48)^3+(50)^3$

apply identity $x^3-y^3=(x-y)(x^2+xy+y^2)$

$= (28-48)((28)^2+(28)(48)+(48)^2)+(50)^3$

$= -20(784+1344+2304)+(50)^3$

$= -88640+(50)^3$

$= -88640+125000$

= 36360

Hence final answer is 36360.