问题
解答题
计算: (1)-8+4÷(-2); (2)(-42)×(
(3)
(4)(-2)2-15×
|
答案
(1)-8+4÷(-2)
=-8+(-2)
=-10;
(2)(-42)×(
-1 6
+3 14
)2 7
=-42×
+42×1 6
-42×3 14 2 7
=-7+9-12
=2-12
=-10;
(3)
-15 3 6
≈3.87-1.82
=2.05
≈2.1;
(4)(-2)2-15×81
=4-1×9
=4-9
=-5.