If the equation given is meant to be x2 − 6x + 11 − x = y − (y + 1), then
simplification of left and right sides gives x2 − 7x + 11 = y − y − 1 or
x2 − 7x + 11 = − 1 or the quadratic equation x2 − 7x + 12 = 0.
Seeking 2 numbers that add to 7 and multiply to 12 will lead to 3 and 4
which enables (x − 3) × (x − 4) or x2 − 7x + 12 = 0 with the solution set
for x as {3,4}.
4 and 3 are also gained as roots of x2 − 7x + 12 = 0 by way of
x = {-(-7) + √[(-7)2 − (4×1×12)]} ÷ (2 × 1) which gives 4.
x = {-(-7) − √[(-7)2 − (4×1×12)]} ÷ (2 × 1) which gives 3.
To be a differential equation, the given equation should
contain differential terms such as dy or dx and derivative
terms such as dy/dx, d2y/dx2, y', or y''.