原式=26×(20+3)+25×(4×4+1)
=26×20+26×3+(25×4)×4+25
=520+78+100×4+25
=598+425
=600+423
=1023
26×23+25×17
=(25+1)×23+25×17
=25×23+1×23+25×17
=25×(23+17)+23
=25×40+23
=1000+23
=1023
26×23+25×17
=25×23+25×17+23
=25×(23+17)+23
=25×40+23
=1000+23
=1023
=(25+1)x23+25x17
=25x(23+17)+23
=25x40+23
=1000+23
=1023
26×23+25×17
=25x(23+17)+23
=25x40+23
=1000+23
=1023