问题
解答题
求下列各式的值: (1)(0.25)-2+8
(2)lg16+3lg5-lg
|
答案
(1)原式=(2-2)-2+(23)
-(24)2 3
+33 4
=24+22-23+3
=16+4-8+3
=15.
(2)原式=lg24+3lg5-lg5-1
=4lg2+3lg5+lg5
=4(lg2+lg5)
=4.
求下列各式的值: (1)(0.25)-2+8
(2)lg16+3lg5-lg
|
(1)原式=(2-2)-2+(23)
-(24)2 3
+33 4
=24+22-23+3
=16+4-8+3
=15.
(2)原式=lg24+3lg5-lg5-1
=4lg2+3lg5+lg5
=4(lg2+lg5)
=4.