Question

42X43.43一43X42.42

Answer 1

42X43.43一43X42.42
=42X（43+0.43）一43X42.42
=42X43+42X0.43-43X42.42
=42X0.43+43X(42-42.42)
=42X0.43-43X0.42=0

Answer 2

原式=42×43×1.01-43×42×1.01
=42×43×1.01-42×43×1.01
=0