[(2x+y)2﹣(2x+y)(﹣y+2x)]÷2y,其中x=4,y=5.
- 
[2-
].




68×268+68
19219×19
53= 103=
203= 0.13=
1
÷0.15= 4.6+4= 3-
=
2013+67= 63= 10.1-1=
=
×2÷
×2=
2019﹣128= 10﹣0.86= 20×0.8= 100÷20%=
10÷0.5=
﹣0.375=
×0.81= 52﹣32=
0.125×5×0.8= 13÷91= 3.14×8= 4.5﹣4.5÷15=
6﹣2
=
=
÷32%=
×8÷
×8=
0.54÷0.9= 3-0.06= 0.21×0.3=
+
=
÷
=
-60%=
+37.5%= 0.32= 499+303≈ 564÷79≈
=
=
= 27÷80%=
=
=
52= 92= 62= 122= 142= 11=