奧數1 1/4x17+6x12.5+10/8+2x1.25

第三個先答對!!!!!!!

1/4x17+6x12.5+10/8+2x1.25=
=>1*17/4+6*12.5+10/8+2.5
=>17/4+75+1.25+2.5
=>4.25+75+1.25+2.5
=>4.25+1.25+2.5+75
=>6.5+2.5+75
=>9+75
=>84

1 1/4x17+6x12.5+10/8+2x1.25

=1.25x17+6x12.5+1.5+2x1.25

=1.25x17+60x1.25+1.25+0.25+2x1.25

=(17+60+1+2)x1.25+0.25

=80x1.25+0.25

=(8x1.25)x10+0.25

=10x10+0.25

=100+0.25

=100.25

1 1/4x17+6x12.5+10/8+2x1.25

=5/4 x17 + 6x25/2 +5/4+2x 5/4

=85/4+300/4+5/4+10/4

=(1/4)(85+300+5+10)

=(1/4)(400)

=100//