Find the cube roots of the following numbers by successive subtraction

1.	Find the cube roots of the following numbers by successive subtraction of numbers:1, 7, 19, 37, 61, 91, 127, 169, 217, 271, 331, 397, …(i) 1728
Answer» (i) 1728 1728 – 1 = 1727 1727 – 7 = 1720 1720 – 19 = 1701 1701 – 37 = 1664 1664 – 91 = 1512 1512 – 127 = 1385 1385 – 169 = 1216 1216 – 217 = 999 999 – 271 = 728 728 – 331 = 397 397 – 397 = 0 Hence ,subtraction is performed 12 times. ∴ Cube root of 1728 is 12.

Find the cube roots of the following numbers by successive subtraction of numbers:1, 7, 19, 37, 61, 91, 127, 169, 217, 271, 331, 397, …(i) 1728

Answer»

(i) 1728

1728 – 1 = 1727

1727 – 7 = 1720

1720 – 19 = 1701

1701 – 37 = 1664

1664 – 91 = 1512

1512 – 127 = 1385

1385 – 169 = 1216

1216 – 217 = 999

999 – 271 = 728

728 – 331 = 397

397 – 397 = 0

Hence ,subtraction is performed 12 times.

∴ Cube root of 1728 is 12.