if a question says is -a a zero of (some equation)
can you just plug in all the x's as -a and see if you get zero?
Yes, to check if -a is a zero of a given equation, you can substitute -a into the equation and see if it evaluates to zero. If it does, then -a is indeed a zero of the equation.
To explain further, let's say you have an equation in the form f(x) = 0, where f(x) is some expression involving x. To check if -a is a zero, you substitute -a into the equation and simplify it. If you end up with f(-a) = 0, then -a is a zero of the equation.
Here's a step-by-step breakdown of the process:
1. Start with the equation f(x) = 0.
2. Replace every instance of x with -a throughout the equation.
3. Simplify the equation to see if it evaluates to 0 when x is replaced with -a.
4. If you get f(-a) = 0, then it means -a is a zero of the equation. Otherwise, if f(-a) ≠ 0, then -a is not a zero of the equation.
It's worth noting that this method works specifically for determining whether -a is a zero of a given equation. There may be other solutions as well, and this method does not guarantee that -a is the only zero.