Answer :
[tex]x-\ amount\ of\ sales\\\\
30+\frac{2}{9}*x=100\ \ \ |Subtract\ 30\\\\
\frac{2}{9}*x=70\ \ \ |*9\\\\
2x=630\ \ \ |:2\\\\x=315\\\\
You\ need\ 315\ sales.[/tex]
the salesperson earns a fixed cost of $ 30 plus 2/9th of his sales
we have to find how many sales he gets to earn $ 100 for one day
so lets say that the number of sales for the day - x sales
and he earns 2/9th of his sales
therefore amount he earns for x sales is - [tex] \frac{2}{9}* x = \frac{2x}{9} [/tex]
this value plus his fixed earnings of $ 30 per day
so the amount he earns is 2x/9 + 30
this equals $ 100
so we can write the following equation
[tex] \frac{2x}{9} + 30 = 100 [/tex]
[tex] \frac{2x}{9} = 100 - 30 [/tex]
[tex] \frac{2x}{9} = 70 [/tex]
2x = 70 * 9
2x = 630
x = 315
so the amount of sales he earns for that day is 315 sales