Question
Question: If 3 is a root of \(x^{2} + kx - 24 = 0\), it is also a root of...
If 3 is a root of x2+kx−24=0, it is also a root of
A
x2+5x+k=0
B
x2−5x+k=0
C
x2−kx+6=0
D
x2+kx+24=0
Answer
x2−kx+6=0
Explanation
Solution
Equation x2+kx−24=0 has one root as 3,
⇒ 32+3k−24=0 ⇒ k=5
Put x=3 and k=5 in option
Only (3) gives the correct answer i.e. ⇒ 32−15+9=0
⇒ 0=0