Answer:

Step-by-step explanation:
Notice that the focus is a points on the vertical axis, that means the parabolla opens vertically, and has the form

Because the parameter
is positive and equal to 0.75. Additionally, the vertex is at the origin, that's why the equation is this simple.
Replacing the parameter value, we have

Therefore, the equation of a parabolla with vertex at the origin and focus at (0, 0.75) is
.
500 + 30% equals 650. 30% of 500 equals 150.
Let n be a number of friends at the perty. If <span>dinner costs $30 per person, then it cost $30n for all friends.
</span>
Robert has booked a banquet hall which costs <span>$200, then his total expenses are $200+30n.
</span>
If the final bill is p, then p=<span>200+30n.
</span>
Answer: p=<span>200+30n.</span>