a student claims that 8x - 2 (4 + 3x) is equivalent to 3x describe all the errors in there steps

step 1: 8x - 8 + 3x
step 2: 8x + 3x - 8
step 3: 11x - 8
step 4: 3x

1 answer

There are many errors in the student's steps.

1. The first error is in step 1. The student incorrectly distributed -2 to (4 + 3x).
The correct distribution should be -2*4 = -8 and -2*3x = -6x, not -8 and 3x.

2. Due to that mistake, the equation from step 1 should be 8x - 8 - 6x.

3. In step 2, again, due to the mistake in step 1, the expression should have been reordered to 8x - 6x - 8, not 8x + 3x - 8.

4. In step 3, when combining like terms, instead of it being 11x - 8, it should have been 2x - 8 due to the mistake in step 1 and 2.

5. Finally, the biggest error is in step 4. After correcting the previous steps, the final expression should be 2x - 8, not 3x. So the student's claim that 8x - 2 (4 + 3x) is equivalent to 3x is incorrect.

These errors could be due to misunderstanding the concept of distribution and combining like terms.