Hello! The error that Clara made was that she didn't combine the r's together. For questions like these, we would combine like terms. The 6b part is correct, because 8b - 2b is 6b. But, the other r needs to be combined with the -4r, and in this case we would add, because subtracting a negative number turns the problem from subtracting to adding. -4r - (-r) is -3r. The correct result is really 6b - 3r.
Answer:
46
Step-by-step explanation:
Since B is the midpoint of AC, the segments AB and BC must have equal length. This means that x + 13 = 2x + 3. Solving this, we see that x = 10. By substituting 10 for x, we see that the length of AB is 23, so the length of AC is 2*23, which is 46.
Answer:
hundreds
Step-by-step explanation: