Answer:Step-by-step explanation:In order here is what I would answer.E being the midpoint is GivenIt says the reason is definition of a midpoint, so we can assume the statement is making use of that. I believe it's DE = EFTaking the statement filled in in the previous step, if we substitute what is given for DE and EF we get what is shown, so the reason would be substitution.It looks like 8x was subtracted from both sides, so subtraction property of equalityIt says the subtraction property was used again, what could have been subtracted? Only thing I see is 5x so subtracting that from both sides would leave -2x = -6Division property is used, and the only thing to really divide by is -2, so doing that gets us x = 3We're substituting 3 for x here, so the reason is substitutionThis is the transitive property, since DE equals the equation, and the equation equals 23, DE = 23 and proof done.Do you think you could do the other parts yourself or would you need further help? If you need more help I will walk you through them rather than just answer.