x*x=24
x=±√24
4:1又1/4=X:0.75
5/4X=4*0.75
5/4X=3
X=3*4/5
X=12/5
10/X=4又1/2:0.8
10/X=9/2÷4/5
10/X=9/2*5/4
10/X=45/8
45/8X=10
X=10*8/45
X=16/9
7又3/4*0.6+2/5*7.75
=7.75*0.6+0.4*7.75
=7.75*(0.6+0.4)
=7.75*1
=7.75
13又7/8-(8.16+1.875)-0.84
=13.875-8.16-1.875-0.84
=13.875-1.875-(8.16+0.84)
=12-9
=3
除号就是比号,