The teacher will be very surprised to see your correct solution 😉
/x pi\ tan|- - --| = 9 \3 6 /
x1 = -pi - 3*acot(9)
x1 = -pi - 3*acot(9)
sum
-pi - 3*acot(9)
=
-pi - 3*acot(9)
product
-pi - 3*acot(9)
=
-pi - 3*acot(9)
-pi - 3*acot(9)
x1 = -97.7213439248053
x2 = -31.7478981994196
x3 = 62.4998814082742
x4 = 34.225547525966
x5 = -88.2965659640359
x6 = 100.198993251352
x7 = -60.0222320817278
x8 = 5.9512136436579
x9 = 71.9246593690436
x9 = 71.9246593690436