Question

If the sum of quadaratic polynomial5x2-kx+8 is 3 then find the value of k​

Answer 1

Hope you understand the answer

Answer provided in the photo above

the value of k=15

Answer 2

GiveN :

• Quadratic Equation is 5x² - kx + 8
• Sum of zeros of equation is 3

To FinD :

• Value of k

SolutioN :

The given quadratic equation is 5x² - kx + 8, and the general form of quadratic equation is ax² + bx + c, On Comparing both the equations we get,

• a = 5
• b = -k
• c = 8

As we know that from for Sum of zeros is :

$\implies \sf{Sum \: of \: zeros \: = \: \dfrac{-b}{a}} \\ \\ \implies \sf{3 \: = \: \dfrac{-(-k)}{5}} \\ \\ \implies \sf{3 \: = \: \dfrac{k}{5}} \\ \\ \implies \sf{k \: = \: 3 \: \times \: 5} \\ \\ \implies \sf{k \: = \: 15} \\ \\ \underline {\sf{\therefore \: Value \: of \: k \: is \: 15}}$