Explanation:
so, first, let's see the factors of 252 :
252 / 2 = 126
126 / 2 = 63
63 / 2 no
63 / 3 = 21
21 / 3 = 7
so, 252 = 2×2×3×3×7 =
= 4×9×7 =
= 36×7 =
= 42×6 =
= 18×14
and others. but these are closest to the given answer options.
A. is wrong. 126^(1/2) is the same as sqrt(126). that is of course not the same as sqrt(252).
B. is wrong. to leave 6 in the square root, the remaining factor is 42. and sqrt(42) is not 7.
C. is wrong. to leave 7 in the square root, the remaining factor is 36. and sqrt(36) is not 18.
D. is correct. see C. sqrt(36) = 6. so, sqrt(252) = sqrt(36×7) = 6×sqrt(7).
E. is correct. 252^(1/2) is exactly the same as sqrt(252). an exponent of 1/n means the nth root.