Which of the following Equation is NOT equivalent to 25x^2 = y^2 - 25?Which of the following Equation is NOT equivalent to 25x^2 = y^2 - 4?  Choose the correct option.
A) 25x^2 + 4 = y^2  B) 75x^2 = 3y^2 - 12  C) 5x = y - 5  D) 25x^2 = (y + 2)(y - 2)  E) x^2 = (y^2 - 4)/25
1) Take the original equation and try to manipulate it so that it becomes 4 of the 5 answers   2) Take each answer choice and see if you can manipulate it to make it into the original equation.   With Answer D, we have...   5X = Y - 5   If we square both sides, we end up with....   (5X)^2 = (Y-5)^2   (5X)(5X) = (Y-5)(Y-5)   25X^2 = Y^2 - 10Y + 25   This is NOT a match for the original equation, so it's the answer that is NOT equivalent. 5x = y - 5
<result>C</result>
Which of the following Equation is NOT equivalent to 25x^2 = y^2 - 25?Which of the following Equation is NOT equivalent to 25x^2 = y^2 - 4?