Question

For what value of k will 7/3 be a root of the 3x2

-13x –k = 0 ?

(a) 14 (b ) 3/7 (c) -7/2 (d) -14​

Answer 1

Answer:

Given equation is: 3x

2+kx+3=0

Here, a=3,b=k,c=3

Now, D=b 2 −4ac=k

2 −4×3×3k 2 −36

We know that a quadratic equation has real and equal roots,

If D=0⇒k

2 −36=0

⇒k 2=36

∴k=± 36

​

=±6

Step-by-step explanation:

Answer 2

Answer: -14

Step-by-step explanation:

$p(x)=3x^{2} -13x-k=0\\p(\frac {7}{3}) =3(\frac{7}{3}) ^{2} -13(\frac{7}{3})-k=0\\3*(\frac{49}{9} )-\frac{91}{3} -k=0\\k=\frac{49}{3} -\frac{91}{3} \\ k=-\frac{42}{3} \\k=-14$