Do real problems or 400 problems in mathematics first? RT starts to do math papers in the rest of the day. Do you want to do real problems or 400 problems first?

Do real problems or 400 problems in mathematics first? RT starts to do math papers in the rest of the day. Do you want to do real problems or 400 problems first?

Do the real problem first, the simulated problem is more difficult than the real one, either Li Yongle or Wendeng. Otherwise, your confidence will be in a mess

17×300= 0.98-0.09= 0.2+0.78=
600×700= 10.2+0.02= 0.15+0.7=
670+250= 10.2+0.2= 9.2-6=
8500÷500= 3.2-3.2= 3.7+2.3=
25×100= 3.2-0.32= 2+2.8=
380-290= 0.35+0.5= 0.35+0.63=
3500÷70= 3.1+3= 3.8+0.38=
7500÷250= 3.8+1= 0.95-0.05=
450+780= 3.1+0.3= 3+0.3=
630÷9= 4.5-0.4= 9.5-5=
330×9= 9.53-1.53= 9.5-0.5=
3.5+2.4= 1-0.95= 0.3+0.27=
0.47+0.13= 4.5+4= 4-0.6=
0.95+0.05= 2.5+3.2= 0.74+0.16=
23×100= 9.8-4.8= 480÷40=
0.53÷100= 5.1+2.3= 125×80=
0.078÷10= 0.52+0.4= 70×12=
0.25×100= 3.4-2.8= 0.6-0.37=
0.052×10= 10+0.08= 1-0.75=
0.5×1000= 7.82+0.3= 13.5+6.5=
3.05×100= 1.2-0.8= 21.6-12.6=
63÷100= 0.83-0.5= 0.76+0.14=
80÷1000= 2.7+0.4= 0.72-0.43=
30×100= 0.92-0.2= 3.5+4.8=
3.5+2.4= 5+0.07= 1-0.61=
0.47+0.23= 0.25+0.75= 3.7+0.33=
0.51+0.33= 1-0.6= 8-4.6=
5.8-3.6= 0.52+0.4= 6.45+5.5=
4.5-1.3= 3.4-2.8= 9.53-1.53=
8.8-6.7= 10+0.08= 9.5-7.3=
7.2+0.8= 7.82+0.3= 8.8-6.7=
9.5-7.3= 1-0.95= 3.4-2.8=
0.96-0.35= 9.53-1.53= 0.25+0.75=
1.2-0.8= 0.83-0.5= 2.7+0
12.5×8＝ 2.3×4＝ 3.25×0＝
0.4×50＝ 30×0.1＝ 2.6×3＝
4.1×2＝ 0.35×0.2＝ 7.5×0.1＝

5100 0.89 0.98 420000 10.22 0.85920 10.4 3.217 0 62500 2.88 4.890 0.85 0.9850 6.1 4.1830 4.8 0.91230 3.4 3.370 4.1 4.52970 8 95.9 0.05 0.570.6 8.5 3.41 5.7 0.92300 5 120.0053 7.4 100000.0078 0.92 8402...

Given the set a = (1,2), B = (x ^ 2-2x + A-1 = 0). B is a subset of a, the scope of finding a is mainly the solution

There are four subsets of A. they are empty sets with 0 elements
The {1}, {2} with one element
The {1,2} with two elements
Now let B be equal to the above four sets
When it's equal to an empty set,
It means that the equation you give has no solution. The equation has no solution if B ^ 2-4ac