Question

If (x+1) is a factor of polynomial
p(x)= 3x²-kx+7
find the value of k

Answer 1

Step-by-step explanation:

x+1=0

x= -1

p(x)=3x^2-kx+7

0=3(-1)^2-k(-1)+7

3+k+7=0

k+10=0

k= -10

Answer 2

Answer:

k= -10

Step-by-step explanation:

x+1 is factor of 3x²-kx+7

∴if x= -1

3x²-kx+7=0

p(-1)=0

∴3×(-1)²-k×(-1)+7=0

3×1+k+7=0

3+k+7=0

∴k+10=0

∴k= -10