Please help with this lol

Aclassmate thinks that solving a system by graphing gives an exact answer when the lines appear to cross at a grid point, but only an approximate answer when they don't. explain why this isn't true.

Do one of the following, as appropriate: (a) find the critical value z subscript alpha divided by 2 , (b) find the critical value t subscript alpha divided by 2 . 99%; nequals 17; sigma is unknown; population appears to be normally distributed.

Acompound inequality is graphed, and its graph consists of all real numbers. which open scentence could have resulted in this solution set r> 3 or r< -2. r< 3 or r< -2. r> 3 or r> -2. r< 3 or r> -2 plz asap