29.3k views
22 votes
If one zero of the quadratic polynomial x²+3x+k is 2, then the value of k is. [ ]

a) 10
b)-10
c)5
d)-5​

2 Answers

6 votes

Answer:

GET READY FOR FIGHT !!!!!

Explanation:

*Intense music in background*

User Alex Epelde
by
3.3k points
13 votes

Answer:

b) -10

Explanation:

x^2 + 3x + k = (x - 2)(x - a)

(x - 2)(x - a) = x^2 - 2x - ax + 2a = x^2 + [-2 - a)x] + 2a

-2 - a = 3

2a = k

a = -5

k = 2(-5) = -10

Answer: b) -10

User Clstrfsck
by
3.2k points