Which two signs should be interchanged to balance the following equation?
646 ÷ 19 – 746 + 20 × 34 = 100
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. − and +.
Given equation: 646 ÷ 19 – 746 + 20 × 34 = 100
Option 1: × and +
After interchanging the expression becomes:
= 646 ÷ 19 – 746 × 20 + 34 = 100
= 34 – 746 × 20 + 34
= 34 – 14920 + 34
= -14852 is not equal to 100.
Option 2: − and +
After interchanging the expression becomes:
= 646 ÷ 19 + 746 − 20 × 34 = 100
= 34 + 746 − 20 × 34
= 34 + 746 − 680
= 100 is equal to 100.
As we have found our answer, there is no need to check further options.
Hence, option 2 is the correct answer.