Question

one zero of x³-7x+6 is 2 find the other one​

Answer 1

Answer:

You don’t need to do any fancy algebra here. That -6 is the product of the three roots with their signs changed. Dividing by 2 (–2 with its sign changed) leaves -3 which is the product of the other two roots with their signs changed. So the other two roots might be 1 or 3 with signs ignored. We try them. 3 works and so does -1. So the other zeros are -1 and 3. (Of course we are lucky and didn’t have to resort to anything more complicated.)

Because -2 is a zero, you can factor out (x-(-2)).

Use long division:

x3+2x2–2x2–4x−3x−6

=(x+2)(x2–2x−3)

And then it's easy to factor a quadratic:

=(x+2)(x+1)(x−3)