75×27+19×25,等于25×3×27+19×25,等于25乘括号81+19,等于25×100,等于2500
解:依题意得算式,
75×27+19×25
=25×3×27+19×25
=25×81+19×25
=25×(81+19)
=25×100
=2500
即75×27+19×25=2500
2500-2500-2500
2500250025002500250025002500
75x27+19x25
=25x3x27+19x25
=25x(3x27+19)
=25x100
=25000