Question

lodi solved the equation 3+x/2=10 and justified each step as shown. identify lodis error and fix his mistake. remember the justification is lodis work as well

Answer 1

It appears that he made a mistake in his justification.

Remember that the Multiple Property of Equality says that we can multiply both sides of an equation by an expression, or the following:

`a = b \Rightarrow a \cdot c = b \cdot c \,\checkmark`

The Subtraction Property of Equality similarily says that we can subtract some expression from both sides of the equation, or the following:

`a = b \Rightarrow a - c = b - c \,\checkmark`

Thus, it would be right for the Subtraction Property of Equality to justify the second step, as this is the step where we subtract something from both sides of the equation, which is 3. Similarly, we should justify the third step with the Multiplication Property of Equality, since this is the step where we multiply both sides of the equation by 2.

Thus, his mistake is that his justifications for steps 2 and 3 are switched around.