168.1/(4.3*2-0.4)
=168.1÷(8.2)
=20.5;
[16分之9-(8分之5-12分之7)]*25分之24
=(9/16-10/16+7/12)×(24/25)
=25/48×(24/25)
=1/2;
7分之5+25分之19*4+25分之21*19
=5/7+(19/25)(4+21)
=5/7+19
=19又7分之5;
2分之1/[5-(2分之1+3分之1)*2.4]
=(1/2)/(5-1.2-0.8)
=1/2/3
=1/6;
求未知数X的值
X分之6.5=13:14;
13x=14×6.5;
x=7;
4分之3X=20分之1X+17.5
15x/20-x/20=17.5;
14x/20=17.5;
x=25;