Question

A movie theater sends out a coupon for 10​% off the price of a ticket. Write an equation for the​ situation, where y is the price of the ticket with the​ coupon, and x is the original price of the ticket. Use pencil and paper. Draw a graph of the equation and explain why the line should only be in the first quadrant. The equation is y =

Answer 1

Answer:

y = 0.9x

Step-by-step explanation:

A movie theater sends out a coupon for 10​% off the price of a ticket, so the price of the ticket with the​ coupon is 100% - 10% = 90% of the original price.

Let

x = original price

y = price of the ticket with the​ coupon

Then

x - 100%

y - 90%

Write a proportion:

$\dfrac{x}{y}=\dfrac{100}{90}$

Cross multiply:

$100y=90x\\ \\y=0.9x$

Since the original price and final price are always greater than 0, then the graph of this equation is in the first quadrant (see attached diagram)