calculations Theory

Assign = + Expr>- Expr> * / + ( ) ID | | ABC... Zlable....Z_I$ 0|1|2|3|41516171819 A) Are these strings accepted? Why? a. Hh = $red1 + R b. lbb=r+ tt5 - 07 B) Derive the string rl = 5+t-(+x) C) Is the grammar ambiguous? Why