Respuesta :
x = number of appointments
y = total amount earned in dollars
The total earnings equation is y = 2x+40
The 2x is from her earning $2 per appointment. If she makes x of them, then she earns 2x dollars. This is on top of the $40 from working the full day.
She wants to earn at least $75. This means she wants to earn $75 or more.
This means,
[tex]y \ge 75\\\\2x+40 \ge 75\\\\2x \ge 75-40\\\\2x \ge 35\\\\x \ge \frac{35}{2}\\\\x \ge 17.5[/tex]
Since x is the number of appointments, and we can't have a fractional number of appointments, we must round up to x = 18. This is the lowest number of appointments she can do and earn $75 or larger.
If x = 17, then
y = 2x+40 = 2*17+40 = 34+40 = 74
which is not 75 or larger
But if x = 18, then
y = 2x+40 = 2*18+40 = 36+40 = 76
which is larger than 75, so we've cleared the hurdle.
We can say the solution set is [tex]x \ge 18[/tex] where x is a whole number. So she could book x = 18, x = 19, x = 20, x = 21, etc as the number of appointments to reach her goal.
In summary, she must schedule at least 18 appointments to earn $75 or more.
Since she makes $2 for every appointment she makes we would need to use 40+2n so she would get $2 per appointment no matter how many appointments she makes. Also, we wouldn't use an equal sign because they didn't say she needed to earn exactly $75. They said she needed to earn "at least" $75. At least means equal to or greater than ≥. So the inequality would be 2n+40≥75. PRO TIP: Any time it asks you to write an inequality you will use either <, >, ≤, or ≥ not an =.An equation uses =, an inequality uses the other symbols