Walmart has a bike on sale for $$150. The sign next to it says that the price is $25 off the original price. What is the original price? Define the variable and equation for the situation. Solve the equation.
This question is from my son's Math test. His answer is as follows:
Let x = original price $x = 150 + 25$; $x = 175$.
His teacher marked it as wrong and rewrote the equation as $x - 25 = 150$ ; $x= 175$.
I don't see how the equation my son wrote is wrong? Could you please help me understand?