Word Problems (Addition/Elimination Method).
Check if my answers are correct.
1.A girl bought 2 CDs and 3 DVDs for $92. Each DVD costs $4 more than the CDs. What is the price of each CD and DVD?
My answer: CDs- $16 and DVDs-$20
2.A boy bought 20 stamps, some for 30 cents and the rest for 20 cents. If he spent $5.50 on the stamps, how many did he buy of each one?
My answer: 30c stamps- 15, 20c stamps- 5
#1 works: 32+60=92
#2 works: 4.50+1.00=5.50
nice work (I guess, since you don't show it, but you did get the right answers!)
To check your answers, let's use the addition or elimination method for solving these problems.
1. A girl bought 2 CDs and 3 DVDs for $92. Each DVD costs $4 more than the CDs.
Let's assign variables to represent the price of a CD and a DVD. Let's say CD = x and DVD = x + $4 (since each DVD costs $4 more).
From the given information, we can write the following equations:
2x + 3(x + $4) = $92 (Total cost of CDs and DVDs is $92)
2x + 3x + 12 = $92
5x = $80
x = $16
So, the price of each CD is $16. Plugging this value into the second equation, we can find the price of each DVD:
DVD = CD + $4
DVD = $16 + $4 = $20
Your answer of CDs - $16 and DVDs - $20 is correct.
2. A boy bought 20 stamps, some for 30 cents and the rest for 20 cents. If he spent $5.50 on the stamps, how many did he buy of each one?
Let's assign variables to represent the number of stamps bought at 30 cents and 20 cents. Let's say 30c stamps = x and 20c stamps = 20 - x (since he bought a total of 20 stamps).
From the given information, we can write the following equation:
30x + 20(20 - x) = $5.50 (Total cost of stamps is $5.50)
30x + 400 - 20x = $5.50
10x = $5.50 - $400
10x = -$394.50
x = -$39.45 (This is not a valid solution, as the number of stamps cannot be negative)
Double-check your calculations for this problem and make sure you've entered the information correctly. Your answer of 30c stamps - 15 and 20c stamps - 5 is incorrect.