问题
解答题
(1)计算:-
(2)已知2a-1的平方根是±3,3a+b-1的算术平方根是4,求12a+2b的立方根. (3)已知a的倒数是-
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答案
(1)原式=2+2+3-4
=7-2
=5.
(2)由题意得,2a-1=9,3a+b-1=16,
解得:a=5,b=2,
故12a+2b=64,64的立方根为4.
(3)由题意得,a=-
,b=0,c=-1,2
则a2+b2+c2=3.
(1)计算:-
(2)已知2a-1的平方根是±3,3a+b-1的算术平方根是4,求12a+2b的立方根. (3)已知a的倒数是-
|
(1)原式=2+2+3-4
=7-2
=5.
(2)由题意得,2a-1=9,3a+b-1=16,
解得:a=5,b=2,
故12a+2b=64,64的立方根为4.
(3)由题意得,a=-
,b=0,c=-1,2
则a2+b2+c2=3.