Answer:
k=10
do long or synthetic division. the quotient = 3x + 22 with remainder 81
with long division first divide x into 3x^2 to get 3x. Then
3x times (x-4) = 3x^2-12x
subtract that from 3x^2+kx to get (k-12)x bring down the -7 to get
(k-12)x -7
you want a remainder of 81, so you want -4 times a constant to = -88 (-7-(-88)=81
4 x 22 =88. 22 is the constant
22=12+k
k=10
Explanation:
lmk if i helped!