Math, Algebra 1

Question

If f(x + 3) = x^2 + kx - 21, what is the value of k?, Where are the zero(s) of f(x + 3)?

Answer 1

It seems like there should be more to this problem than what you are sharing (perhaps what f(x) is). If what you have posted is all there is, then there are lots of solutions.

For instance, if f(x) = x² - 30 then:

f(x + 3) = (x + 3)² - 30 or

x² + 6x + 9 - 30 or

x² + 6x - 21

so in that case, k = 6.

But how about when f(x) = x² - 2x - 24, then:

f(x + 3) = (x + 3)² - 2(x + 3) - 24 or

x² + 6x + 9 - 2x - 6 - 24 or

x² + 4x - 21

so in this case, k = 4

Answer 2

Without x; I don't know.