Tracy buys lamps for $3 each and one basket for $2. The total cost was $22. How many lamps did Tracy buy? Write the equation to represent this situation.

Question

Help me!!!!

Answer 1

Hello Chloe, try following this method for writing down your equation:

• (Total cost) = (the cost of the lamps) + (the cost of the baskets)

 

If that makes sense to you, start substituting the phrases inside the parentheses above with numbers and variables. For example, the problem gives us the total cost, $22. So, we can rewrite the above equation like so:

• ($22) = (the cost of the lamps) + (the cost of the baskets)

Next, we could work with the baskets. The problem tells us that Tracy bought one basket for $2. So, the cost of the baskets (well, really just one basket in this case) was $2:

• ($22) = (the cost of the lamps) + ($2)

Finally, we need to write something that represents the cost of the lamps. If Tracy bought L lamps, and each lamp costs $3, then does it seem right that the total cost of the lamps would be $3 times L?

• ($22) = ($3 × L ) + ($2)

We can drop the dollar signs, the multiplication sign, and the parentheses now, just to make our equation look simpler:

• 22 = 3L + 2

From here, solve for L, remembering that we named L to represent the number of lamps Tracy bought. For the numbers that you've given us in the problem description, you'll get an answer that doesn't really make any sense:

• L = 20/3, or 6.66666667 lamps

But if you redo this problem using the actual numbers from your assignment, you should arrive at a whole number answer.

 

Best of luck! I hope this method helps you with your other word problems.

Answer 2

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Answer 3

3L + 2 = 22

 

3L = 20

 

This would mean that you would purchase 20/3 lamps which doesn't make sense since 20/3 is not an integer.