a)475/100+37/100+12,5/100+163/100+37,5/100+50/100
=4,75+0,37+0,125+1,63+0.375+0,5
=(4,75+1,63+0,5)+(0,125+0,375)
=6,88+0,5
=7,38
b)/2x4/x1/2x/3x/5x1/7
--------------------------
4x1/2x3/x5/x4/x1/7x2/
mấy cái / này là gạch đi nha
còn=1/4
 

a) 19/4 + 37/100 + 1/8 + 163/100 + 3/8 + 1/2
= 19/4 + ( 37/100 + 163/100) + (1/8 + 3/8) + 1/2
= 19/4 + 2 + 1/2 + 1/2
= 19/4 + 2 + (1/2 + 1/2)
= 19/4 + 2 + 1
= 31/4
b) 8x12x15x17 / 4x36x20x34
= 2x4x12x3x5x17 / 4x12x3x4x5x17x2
= 4
c) 4x145+4x55 / 2x215+2x85
= 4x(145+55) / 2x(215+85)
= 4x200 / 2x300
= 2x2x2x100 / 2x3x100
= 4/3