The following equation is incorrect. Which two signs should be interchanged to correct the equation?
12×4−6÷7+18=19
- A+ and ×
- B+ and ÷
- C÷ and −
- D− and +
Solution & Step-by-step Explanation
Let's test the options to see which interchange balances the equation to yield 19:
Option C: Interchange ÷ and −
The equation becomes:
12×4÷6−7+18
Applying BODMAS rules:
12×(
6
4
)−7+18
12×
3
2
−7+18
4×2−7+18
8−7+18=1+18=19
Since LHS = RHS = 19, interchanging ÷ and − corrects the equation.
Option C: Interchange ÷ and −
The equation becomes:
12×4÷6−7+18
Applying BODMAS rules:
12×(
6
4
)−7+18
12×
3
2
−7+18
4×2−7+18
8−7+18=1+18=19
Since LHS = RHS = 19, interchanging ÷ and − corrects the equation.