Question

which function has real zeros at x = 3 and x = 7? f(x) = x2 4x – 21 f(x) = x2 – 4x – 21 f(x) = x2 – 10x 21 f(x) = x2 – 10x – 21

Answer 1

Hello,

f(x)=(x-3)(x-7)=x²-10x+21

Answer C

Answer 2

Function which has real zeros at x = 3 and x = 7 is:

f(x)= x²-10x+21

Explanation:

function has real zeros at x = 3 and x = 7

⇒ (x-3)(x-7)=0

⇒ x(x-7)-3(x-7)=0

⇒ x²-7x-3x+21=0

⇒ x²-10x+21=0

f(x)= x²-10x+21 has real zeros at x=3 and x=7

Hence, function which has real zeros at x = 3 and x = 7 is:

f(x)= x²-10x+21