Banners at the school store were on sale for $3 off the rugular price. louis brought 4 banners on sale and paid a total of $18. write and solve an equation to find the regular price of one banner

$7.50

Step-by-step explanation:

4 x 3.00 = $12.00  3.00 off the regular price makes it 12.00 for all the banners

12.00 + 18.00 = 30.00   you add the sale price with the 12.00 to get the total of each banner before the store gave the sale price.

30.00 divide by 4 = 7.50   to find out what the regular price of the banner you divide by the total of banners you bought to get the price of each banner before the sale.  

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.