30=1/2 inch
60=1/2x2=1 inch
90=1/2x3=1 1/2
shortest side is 1/2 inch, medium side is 1 inch, longest is 1 1/2
For an amount of sales of $5,000, the two salary choice will be equal
Let the amount of sales be $x
The 3% she will receive will be;

We add this to the base salary and equate to the former monthy salary
We have this as;
The current sale price would be $123.60.
20% of $618 is 123.6. So turn that into dollars and cents and you get $123.60
3 * 1 * -1 because 3 times one is 3 and that times a negative turns it into a negative. ( positive * negative = negative)