四年级数学
(1)简便计算:75+45*92+17 (2)递等式:5*44+4*45
1)简便计算:75+45×92+17 =(75+17)+45×92 =92×1+45×92 =(45+1)×92 =46×92 =4232 (2)递等式:5×44+4×45 =5×4×11+4×5×9 =5×4×(11+9) =20×20 =400。
(1)简便计算:75+45*92+17 =75+17+45*92 =92+45*2*46 =90+2+90*46 =90+90*46+2 =90*47+2 =4230+2 =4232 (2)递等式:5*44+4*45 =5*11*4+4*45 =55*4+4*45 =4*(55+45) =4*100 =400
75+45*92+17=13080 5*44+4+54=400
答:9999x9999+19999=9999x(10000-1)+19999=9999x10000-9999+19999=99990000+(19999-9999)...详情>>
答:详情>>