The expression 320 + 0.08x shows the earning of a salesperson for her weekly sales.
To earn at least $1000, we have:
320 + 0.08x > =1000
Subtracting 320 from both sides, we get:
0.08x >= 680
Now we need to Divide the above expression by 0.08 both sides,
So, we get:
x >= 8500
Therefore, to earn at least $1000 in one week, the salesperson needs the sales of greater than or equal to $8500.
