Answer:
100 should be added to 'complete the squre'
Step-by-step explanation:
[tex] {x}^{2} - 20x + 24 = 0 \\ ( {x}^{2} + 2 \times 10 \times x + {10}^{2}) - {10}^{2} + 64 = 0 \\ {(x - 10)}^{2} - 100 + 64 = 0 \\ {( x - 10)}^{2} - 36 = 0 \\ {(x - 10)}^{2} = 36 \\ (x - 10) = \pm 6 \\ x = 10 \pm 6 \\ x = 10 + 6 \: \: or \: \: x = 10 - 6 \\ x = 16 \: \: or \: \: x = 4[/tex]
