(2) Say the meaning of the formula of the following letters.
①8x means (eight x's are added) and also means (I don't know).
② The square of x (the symbol 2 representing the square in the upper right corner can't be typed,) means (x times x).
③2x
4 means (2 x's are added and 4 is added).
(3) first judge right and wrong, and then correct.
1. 18 The number less than x is 18.
3x .（
×
)
Correction: 3x- 18
Second, omitting the multiplication sign, x×6-x×2 can be written as 6x square -x square. (
×
)
Correction: x squared times 6-2x.
Three. 3x-6=3(x-6)(
×
)
Four. 5a
5b-3c=5(a
b)-3c(
√
)
Correction: