Question

An online app charges $0.99 to download a song and $7.99 membership fee. (A)Write an expression that gives the total cost in dollars to download “s” songs. (B)Then, find the cost of downloading 12 songs. Incorrect work/solutionCorrect work/solution (A) s(0.99 + 7.99) = 0.99s + 7.99s = 8.98s = (B) 8.98(12) = 8.98 x 12 = $107.76 for 12 songs Part A:Explain what this student did incorrectly.

Answer 1

Answer: The student correctly wrote an expression to find the total cost of downloading "s" songs. The expression is: 0.99s + 7.99. However, they made a mistake when they simplified the expression to 8.98s. The expression should have remained as 0.99s + 7.99, because the $7.99 membership fee does not change regardless of how many songs are downloaded.

In Part B, the student correctly used the expression to find the cost of downloading 12 songs. They multiplied 8.98 by 12 and got the correct answer of 107.76.

Explanation: