1 . 5.2*49+4.9*48
=5.2*4.9*10+4.9*48
=4.9*(52+48)
=4.9*100
=490
2. 15.37*6.88-9.37*6.88+15.37*3.12-9.37*3.12
= 6.88*(15.37-9.37)+3.12(15.37-9.37)
=(6.88+3.12)(15.37-9.37)
=10*6
=60
简便算如下!数学的简便算!求简便算法、式!急急!
1 . 5.2*49+4.9*48
=5.2*4.9*10+4.9*48
=4.9*(52+48)
=4.9*100
=490
2. 15.37*6.88-9.37*6.88+15.37*3.12-9.37*3.12
= 6.88*(15.37-9.37)+3.12(15.37-9.37)
=(6.88+3.12)(15.37-9.37)
=10*6
=60