Question

11x+25=7x+15how many solutions are there to this equation

Answer 1

Just 1. The reason is simple.
Both can be constructed as lines on a cartesian plane.
They are not parallel and they are not equivalent. So it follows they must intersect exactly once. Of course you can solve it and if you get a unique answer for x, then it has one solution. If you try and you get 0 = 5 for 0 = any number other than zero, then there is no solution.since 0 can't be not equal to 0. This is the case of the lines being parallel, and never touching. If you get a 0=0, then this agrees regardless of x and so you have infinite solutions for x. This can be thought of as both lines lining on top of each other, being exactly the same.