Question

evaluate
${(99)}^{3}$
using suitable identity​

Answer 1

Answer :

${(a + b)}^{3} = {a}^{3} + \: {b}^{3} + 3ab(a + b)$

=(99)³

=(90+9)³

• a=90
• b=9

using identity ...

(a+b)³=a³+b³+3ab(a+b)

=(90)³+(9)³+3*90*9(90+9)

=729000+729+240570

=970299

(99)³=970299