Question

How do you solve the equation `25+x^2+10x=0` by graphing?

Answer 1

`x=-5`

Explanation:

Graph the function `y = 25 + x^2 + 10x`:

graph{x^2+10x+25 [-12.79, 7.21, -2.88, 7.12]}

The solution(s) to `x` is when `y=0`. That is, when the graph touches or crosses the x-axis.

In this case, the graph only touches the `x` axis at `x=-5`, and is always positive otherwise. So, we have one solution:

`x = -5`

Final Answer