Explain why, if the price of something is increased by 10% and then the new price is reduced by 10%, the final price is less than the original price.

Let's say something costs 100 pounds. If the cost is increased by 10 percent then it goes to 110 pounds. 10 percent of 110 is 11 so 110-11 is 99 (less than earlier. There you go.

the answer is 62

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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.