Question

Solution please... ​

Answer 1

Answer:

d)2,7

Step-by-step explanation:

expanding it by row 1 we get,

0=x(x*x-12)-3(2*x-7*2)+7(2*6-7*x)

0=x(x^2-12)-3(2x-14)+7(12-7x)

0=x^3-12x-6x+42+84-49x

0=x^3-67x+126

0=(x+9)(x^2-9x+14)

one root is -9

for other roots

x^2-9x+14=0

x^2-2x-7x+14=0

x(x-2)-7(x-2)=0

(x-2)(x-7)=0

other roots are 2 and 7