Answer:
145 cups of lemonade; 2x+1.50y=425, where y=90
Step-by-step explanation:
Let us first set up an equation, where <em>x</em> represents number of cups of lemonande, and <em>y</em> represents number of candy bars. We know that every cup of lemonade costs $2, every candy bar sold costs $1.50, and that Marcia sold a total of $425. We now have equation:

However, we actually know how many candy bars Marcia sold. Therefore, our y value is 90. Let's rewrite the equation:

<u>Therefore, Marcia sold 145 cups of lemonade.</u>
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<em>I hope this helps! Let me know if you have any questions :)</em>