If one of the roots of quadratic equation 7y 2 - 50y + k = 0 is 7, then what is the value of k?
Correct Answer: 7
Explanation:
Given quadratic equation is
7y2 - 50y + k = 0
If one root is 7, then it will satisfy the equation i.e putting y = 7 in equation
7 x (7)2 - 50 x 7 + k = 0
⇒ 7 x 49 - 350 + k = 0
⇒ 343 - 350 + k = 0
∴ k = 7