If x+3 is a factor of 3x^2-4kx-4k^2 then find k
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let q(x) = x+3
p(x) = 3x²-4kx-4k²
put q(x) =0
x+3 =0
x = -3
put x=-3
3(-3)² - 4k(-3) -4k² =0
27+12k-4k² =0
-4k²+12k+27
by splitting middle yerm
-4k²+12k+27=0
-(4k²-12k-27)=0
4k²-12k-27 =0
4k²-18k+6k-27 =0
2k(2k-9)+3(2k-9)=0
(2k-9) (2k+3)=0
2k-9=0 or 2k+3=0
k=9/2 or k=-3/2
p(x) = 3x²-4kx-4k²
put q(x) =0
x+3 =0
x = -3
put x=-3
3(-3)² - 4k(-3) -4k² =0
27+12k-4k² =0
-4k²+12k+27
by splitting middle yerm
-4k²+12k+27=0
-(4k²-12k-27)=0
4k²-12k-27 =0
4k²-18k+6k-27 =0
2k(2k-9)+3(2k-9)=0
(2k-9) (2k+3)=0
2k-9=0 or 2k+3=0
k=9/2 or k=-3/2
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