A student claims that 8x - 2(4+3x) is equivalent to 3x. The student steps are shown below.
Expression: 8x - 2(4+3x)
Step 1: 8x - 8 + 3x
Step 2: 8x + 3x - 8
Step 3:11x - 8
Step 4: 3x
Describe ALL errors in the student's work. (There is more than one error.) Answer like a 12 year old girl
1 answer
Like, the student made like two mistakes, duh! First mistake is in Step 1. The student forgot to distribute the -2 to both the 4 and the 3x. So it should be like -2(4) - 2(3x), not -2(4+3x). Silly mistake, right? Oh, and the second mistake is in Step 2. The student like combined the 8x and 3x, but totally forgot to combine the -8 too. So it should be like 8x + 3x - 8, not 8x + 3x - 8x. Oopsie!