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2.2.3 Squares, Square Roots, Cube and Cube Roots, PT3 Practice

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Question 10:
(a) Find the value of √0.09(b) Calculate the value of (57×√49)2

Solution:
(a)√0.09=√9100=310=0.3(b)(57×√49)2=(57×7)2                  =52                  =25

Question 11:
(a) Find the value of 3√−127(b) Calculate the value of (7+3√−8)2

Solution:
(a) 3√−127=3√−13×−13×−13=−13(b)(7+3√−8)2=[7+(−2)]2                 =52                 =25

Question 12:
(a) Find the value of (−14)3.(b) Calculate the value of (4.2÷3√27)2.

Solution:
(a)(−14)3=−14×−14×−14           =−164(b)(4.2÷3√27)2=(4.2÷3)2                    =1.42                    =1.4×1.4                    =1.96

Question 13:
(a) Find the value of 3√0.008.(b) Calculate the value of 32×3√−6427.

Solution:
(a) 3√0.008=3√81000           =210           =0.2(b) 32×3√−6427=93×−43                =12

Question 14:
(a) Find the value of (−34)3.(b) Calculate the value of 3√21027÷(22−32).

Solution:
(a) (−34)3=−34×−34×−34           =−2764(b) 3√21027÷(22−32)=3√6427÷(4−9)                           =43÷−5                           =43×−15                           =−415