问题
解答题
(1)计算:(
(2)已知:(x-15)2=169,(y-1)3=-0.125,求
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答案
(1)原式=3
+3
-23 3
+3
-35 5 5
=
-4 3 3
;14 5 5
(2)∵(x-15)2=169,
∴x-15=±13,
即x=15±13,
x=28或2,
∵(y-1)3=-0.125,
∴y-1=-0.5,即y=1-0.5=0.5.
①当x=28,y=0.5时,原式=
-28
-28
=3;3 -27
②当x=2,y=0.5时,原式=
-2
-2
=1.3 -1