Question

19³-10³-9³Evaluate using a suitable algebraic identity.​

Answer 1

we know the formula (a³+b³+c³) = (a+b+c)(a²+b²+c²-ab-bc-ca)+(3abc)

so, here a= 19, b= -10, c= -9.

(19³+(-10)³+(-9)³ = (19+(-10)+(-9))(19²+(-10)²+(-9)²-(19)(-10)-(-10)(-9)-(-9)(19)) + 3(19)(-10)(-9)

= (10 -10 -9)(361 -100 +81 +190 - 90 + 171)+ (5130)

= (-9)(5743)

= 51687

THIS IS YOUR ANSWER HOPE YOU UNDERSTAND ........ AND FELT HAPPY

I DID THIS WITH MY PLEASURE......