You missed the equations......
2x2 − 32 = 0.............a
4x2 − 100 = 0...........b
x2 − 55 = 9...............c
x2 − 140 = -19..........d
2x2 − 18 = 0.............e
Answers
a => x = (+4,-4)
b => x = (+5,-5)
c=> x = (+8,-8)
d => x = (+11,-11)
e => x = (+3,-3)