The function f is defined by f(x)=x^2+3x-10
if f(x+5)=x^2+kx+30, then k= ?
find the smallest zero of f(x+5) x=?

k = 13

smallest zero = -6

Step-by-step explanation:

f(x) is basically the function of x.

x could be any integer. f(x) is the solution of the function of x.

f(x) is defined as x² + 3x - 10

f(x) = x² + 3x - 10

Now, f(x+5) = x² + kx + 30

This statement here says that if the value of x is x+5, then the answer would be x² + kx + 30.

f(x) = x² + 3x - 10

f(x+5) = (x+5)² + 3(x+5) - 10

f(x+5) = x² + 10x + 25 + 3x + 15 - 10

f(x+5) = x² + 13x + 40 - 10

f(x+5) = x² + 13x + 30

x² + 13x + 30 = x² + kx + 30

hence, k = 13

Smallest zero = The smallest x value.

f(x+5) = x² + 13x + 30

Let's take f(x+5) = 0

x² + 13x + 30 = 0

which two numbers products give us 30 and add up to 13?

== 6 and 5

(x+6)(x+5) = 0

x+6 = 0

x = -6

x+5 = 0

x = -5

The two solutions are -6 and -5

The smallest out of these two is -6.