Question

( 2x - 3 ) ao quadrado = 25 , Qual é a resposta???

Answer 1

Resposta:

(2x - 3)² = 25

2x1 - 3 = 5

2x1 = 8

x1 = 8/2 = 4

2x2 - 3 = -5

2x2  = -2

x2 = -1

S = (-1, 4)

Answer 2

$(2x - 3) {}^{2} = 25 \\ (2x) {}^{2} + 2 \times 2x \times - 3 + ( - 3) {}^{2} = 25 \\ 4 {x}^{2} - 12x + 9 = 25 \\ 4 {x}^{2} - 12x + 9 - 25 = 0 \\ 4 {x}^{2} - 12x - 16 = 0 \\ {x}^{2} - 3x - 4 = 0 \\ a =1 \\ b = - 3 \\ c = - 4 \\ ∆=( - 3) {}^{2} - 4 \times 1 \times - 4 \\ ∆=9 + 16 = 25 \\ \\ x1 = \frac{ - ( - 3) + \sqrt{25} }{2} = \frac{3 + 5}{2} = \frac{8}{2} = 4 \\ x2 = \frac{ - ( - 3) - 5}{2} = \frac{3 - 5}{2} = \frac{ - 2}{2} = - 1$