Instructions: For each given equation, identify the correct interchange (of signs or numbers) from the options that makes the equation true. 5 × 2 + 9 - 8 = 20
Show answer & explanation
Correct answer: B
Explanation
Given:
5 × 2 + 9 − 8 = 20
Switch 2 and 9 →
5 × 9 + 2 − 8 = 45 + 2 − 8 = 39
Switch 5 and 8 →
8 × 2 + 9 − 5 = 16 + 9 − 5 = 20
Switch 9 and 8 →
5 × 2 + 8 − 9 = 10 + 8 − 9 = 9
Switch × and + →
5 + 2 × 9 − 8 = 5 + 18 − 8 = 15
Switch 5 and 8