4.3×3.7+0.63×43＝43×0.37+0.63×43＝43×（0.37+0.63）＝43×1＝43
4.3×3.7+0.63×43=4.3×3.7+6.3×4.3=4.3x(3.7+6.3)=4.3x10=43
