Question

Pfff me ajudeeeeeeeem!!! ​

Answer 1

5)

a)

${(PT)}^{2} = PA \times PB \\ \\ {x}^{2} = (10 + 11) \times 11 \\ \\ {x}^{2} = (21)11 \\ \\ {x}^{2} = 231 \\ \\ \blue{x = \sqrt{231} \: u.c.}\\ \\ou\\ \\\blue{ x \cong15,1987\:u.c.}$

b)

${(PT)}^{2} = PA \times PB \\ \\ {6}^{2} = ( 9 + x)x \\ \\ 36 = 9x + {x}^{1 + 1} \\ \\ 36 = 9x + {x}^{2} \\ \\ 9x + {x}^{2} = 36 \\ \\ {x}^{2} + 9x - 36 = 0 \\ \\ \Delta = {b}^{2} - 4ac \\ \\ \Delta = {9}^{2} - 4(1)( - 36) \\ \\ \Delta = 81 + 144 \\ \\ \Delta = 225 \\ \\ Bhaskara \\ \\ \dfrac{ - b \pm \sqrt{ \Delta} }{2a} \\ \\ \dfrac{ - 9 \pm \sqrt{225} }{2(1)} \\ \\ \dfrac{ - 9 \pm15}{2} \\ \\ x1 = \dfrac{ - 9 + 15}{2} \\ \\ x1 = \dfrac{6}{2} \\ \\ \blue{ x1 = 3\:u.c.} \\ \\ x2 = \dfrac{ - 9 - 15}{2} \\ \\ x2 = \dfrac{ - 24}{2} \\ \\ x2 = - 12 \: (descartamos \: por \: ser \: comprimento.)$

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