Question

without actual calculation the cubes find the value of each of the following (0•2)-(0•3)+(0•1)3​

Answer 1

Answer:

(i) (30)3 + (20)3 + (- 50)3 We know that a3 + b3 + c3 = 3abc, if a + b + c = 0 Here 30 + 20 – 50 = 0 i.e. a + b + c = 0 ⇒ (30)3 + (20)3 + (- 50)3 = 3 x (30) x (20) x (- 50) = – 90000 (ii) (- 15)3 + (28)3 + (- 13)3 We know that a3 + b3 + c3 = 3abc, if a + b + c = 0 Here a + b + c = – 15 + 28 + (- 13) = 0 (- 15)3 + (28)3 + (- 13)3 = 3 x (- 15) x 28 x (- 13) = 16380