In the equation 17 - 15 x 5 = 250, the answer is incorrect because the signs are jumbled. Which two mathematical signs should be interchanged so that the equation becomes correct?

Introduction / Context:
This question asks us to fix an incorrect equation by interchanging two operation signs. The numbers must stay in the same order, but two of the symbols among =, × and − are swapped. We must identify which swap produces a mathematically true statement.

Given Data / Assumptions:

• Original equation: 17 - 15 x 5 = 250.
• The numerical values 17, 15, 5 and 250 must remain in place.
• We may interchange exactly two of the signs as specified in each option.
• Standard operator precedence applies after the swap.

Concept / Approach:
We systematically test each suggested pair of interchanges. For each option, we replace every occurrence of the two selected symbols throughout the expression and then evaluate the new equation. The correct choice is the one that yields a true equality.

Step-by-Step Solution:
Option (a): interchange = and ×. Expression becomes 17 - 15 = 5 x 250. Left side is 2, right side is 1250, so this is false. Option (b): interchange + and −. There is no plus sign in the equation, so the expression stays 17 - 15 x 5 = 250, which is still incorrect. Option (c): interchange = and −. Expression becomes 17 = 15 x 5 - 250. Right side is 75 - 250 = -175, not 17, so false. Option (d): interchange × and −. The first minus becomes × and the × becomes −, giving 17 x 15 - 5 = 250. Evaluate left side: 17 x 15 = 255, then 255 - 5 = 250. So 17 x 15 - 5 = 250 is a true equation.

Verification / Alternative check:
We see that only option (d) reorganises the operations so that the arithmetic is consistent with the target value 250. All other interchanges lead to left and right sides that clearly differ, even without complex calculations.

Why Other Options Are Wrong:
Options (a) and (c) yield equations where the left side is a small number (such as 2 or 17) and the right side is very large or negative, so they are clearly invalid. Option (b) changes nothing because there is no plus sign to swap, leaving the erroneous original equation unchanged.

Common Pitfalls:
Sometimes candidates only change the first occurrence of a sign instead of every occurrence, or they ignore operator precedence when checking the result. Properly interchanging all instances and then computing with correct precedence avoids these mistakes.

Final Answer:
To make the equation correct we must interchange the signs x and -.