Is this a textbook error or...
I'm currently going through some questions in my textbook and came across a question on a quadratic and linear simultaneous equation.
Solve the equation:
x + y = 1
x^2 + y^2 = 16
I am not interested in the question itself but rather the explanation the book gives me which says after a couple of steps shows the equation:
2x^2 - 2x -15 = 0
Then it tells me to divide the equation by 2 and says when you divide the equation by 2 you will get:
x^2 - x - 15 = 0
I'm confused because i thought the -15 would also have to divide by two...
is it the book or am i missing something serious here?