Question

Luis stated that the sum of -25 and 18 is 7. Is he correct, why? If he is incorrect, what was his error and what is the correct answer?

A. He is correct.
B. He is incorrect; he forgot to add the negative sign.
C. He is incorrect; his error was in the subtraction.
D. He is incorrect; the correct answer is -7.

Answer 1

To determine whether Luis is correct in stating that the sum of -25 and 18 is 7, we need to add -25 and 18. When adding two numbers, we consider their signs. In this case, -25 and 18 have different signs, so we subtract the smaller absolute value from the larger absolute value and use the sign of the larger number. The correct sum of -25 and 18 is -7.

Step-by-step explanation:

To determine whether Luis is correct in stating that the sum of -25 and 18 is 7, we need to add -25 and 18. When adding two numbers, we consider their signs:

1. If both numbers have the same sign, we add their absolute values and use the common sign result. For example, -4 + (-2) = -6.
2. If the numbers have different signs, we subtract the smaller absolute value from the larger absolute value and use the sign of the larger number. For example, -5 + 3 = -2.

In this case, -25 and 18 have different signs. Thus, we subtract the smaller absolute value, which is 18, from the larger absolute value, which is 25. The result is the sign of the larger number, which is -25. Therefore, the correct sum of -25 and 18 is -7. Therefore, Luis is incorrect, and the correct answer is option D: He is incorrect; the correct answer is -7.