Question

Resolva a equação log 1/2 (x2+4x-5) = -4

Answer 1

(1/2) -⁴ = x ² + 4x -5

2 ⁴ = x ² + 4x -5

16 = x ² + 4x -5

x ² + 4x -21 = 0

Δ = 4 ² -4.1.-21 = 16+84 = 100

x = (-4 ± √100)/2.1

x’ = -4-10/2 = -14/2 = -7

x” = -4+10/2 = 6/2 = 3

S = { 3, -7}