Question

What is the only solution of 2x2 + 8x = x2 – 16?

Answer 1

(-4,-4)

Explanation:

Answer 2

Simplify and solve quadratic equation:


`2x^2+8x=x^2-16 => x^2+8x+16 => (x+4)^2=16 => x={-4,-4}`
So numerically the only solution is x=-4.

However, mathematically, there are two solutions, {-4,-4}, or x=4,multiplicity 2.