用简便方法计算1.4²×9-2.3²×36

2024-12-20 01:28:52
推荐回答(2个)
回答1:

1.4²×9-2.3²×36
=1.4²×9-2.3²×4x9
=(1.4²-2.3²×4)9
=(1.4²-4.6²)9
=(1.4+4.6)(1.4-4.6)9
=6x(-3.2)x9
=(-19.2)x(10-1)
=-192+19.2
=-192+20-0.8
=-172.8

回答2:

啥叫简便啊 最简单的计算器 其他的就拆开算 参考:
1.4²×9-2.3²×36
=(1.4×3)²-(2.3×6)²
=4.2²-13.8²
=(4.2+13.8)×(4.2-13.8)
=18×(-9.6)
=172.8