Let's write and equation for both cases.
In plan 1, it is 500 plus 3% comission. 3% is equivalent to multiply the amount it sale in the week, "x", by 0.03.
So, the equation for plan 1 is:
[tex]p_1=0.03x+500[/tex]For plan 2, there is no fixed value, only comission of 5%, which is equivalent of multiplying the weekly sales, "x", by 0.05, so the equation is:
[tex]p_2=0.05x[/tex]For both plans to result in the same salary, we have:
[tex]\begin{gathered} p_1=p_2 \\ 0.03x+500=0.05x \\ 0.05x-0.03x=500 \\ 0.02x=500 \\ x=\frac{500}{0.02} \\ x=25,000 \end{gathered}[/tex]So, for both plans to result in the same salary, she have to sale 25,000 in a week.
