Find the unknown number 14x + 12x = 58 & nbsp; 65x = 2.43.8 + 1.23.2x-4 × 3 = 52.5

Find the unknown number 14x + 12x = 58 & nbsp; 65x = 2.43.8 + 1.23.2x-4 × 3 = 52.5

（1）14X+12X=58，      （14+12）X=58，             34X=58，         34X×43...

0.45: x = 3 / 20:1 / 3 (find the unknown x)
Note:
This symbol is the comparison sign

0.45:x=3/20:1/3
3x/20=0.15
3x=3
x=1

Think about a number, add 52.8 to it, multiply by 5, subtract 3.9343, divide by 0.5, and subtract the one you think about

Wrong title:
Think about a number, add 52.8 to it, multiply by 5, subtract 3.9343, divide by 0.5, and subtract ten times the number you think about
[(x+52.8)*5-3.9343]/0.5-10x
=520.1314

(1 / 1998-1) (1 / 1997-1) (1 / 1996-1) etc. (1 / 1001-1) (1 / 1000-1) =?)
Detailed process

(1 / 1998-1) (1 / 1997-1) (1 / 1996-1) etc. (1 / 1001-1) (1 / 1000-1)
=(- 1997 / 1998) (- 1996 / 1997) (- 1995 / 1996) and so on (- 1000 / 1001) (- 999 / 1000)
A total of 999 items, there are 999 minus signs, multiplication is still negative
=-999/1998
=-1/2