Resolva as equações, nos reais, usando a estratégia que julgar mais adequada. a) x2 – 81 = 0 S = {-9; 9} b) 3y2 – 75 = 0 S = {-5; 5} c) – x2 + 4 = 0 S = {-2; 2} d) x2 – 5 = 0 S={- 5 ; 5 } e) x2 + 4 = 0 S = { } f) 3x2 + 5x = 0 S= {-5/3 ; 0} g) x2 – x = S = {0; 1} h) – 4x2 – 12x = 0 S = {-3; 0} i) S= {- (3y – 4) (3y + 1) = 14 – 9y2 ; 2 } j) (2x +3) (- x + 5) = 0 S= {-5; -3/2} k) (x – 1) (2x – 8) = 0 S = {1; 4} l) (x – 3) (x – 7) = 21 S = {0; 10} m) (x + 10)2 = 0 S = {-10} n) (3x – 27)2 = 0 S = {9} o) (x 2) 4 2 - = S = {0;4} p) (7 – x)2 = 9 S = {4; 10} q) x2 – 6x + 9 = 0 S = {3} r) 4x2 + 4x + 1 = 0 S = {-1/2} s) x2 + 12x + 36 = 81 S = {-9;-3} t) 9x2 + 12x + 4 = 9 S={-5/3; 1/3} u) x2 + 6x = 16 S = {-8; 2} v) x2 – 4x – 5 = 0 S = {-1; 5} w) x2 + x + 20 = 0 S = { } x) x2 + 9x + 14 = 0 S = {–7, –2} y) y2 – 3y – 10 = 0 S = {–2, 5} z) (x + 4)2 = 9x + 22 S = {–2, 3}BOM ESTUDO!