" A matemática é o alfabeto com que Deus escreveu o universo". Galileu Galilei
10.1) +- 310.2) +- 1310.3) +- -25/4Wilson Silva 9ºA2
10.1-(x-3)^2 + 3 = 3(7-2x)(=) x^2 + 2(x-3) + (-3)^2 (=) x^2 -6x + 9 + 3 = 3(7-2x)(=) x^2 -6x + 9 + 3 = 21-6x(=) x^2 = 21-9-3 (=) x^2 = 9 (=) x = +/- V9(=) x = +/- 3 V -3 10.2x(x-3)/2 = -x(=) x(x-3) = 2(-x) (=) x^2 -3x = -2x (=) x^2 = -2x + 3x (=) x^2 = 1 (=) x = +/- V1(=) x = +/- 1 V -1 10.3 (2x + 3) (2x - 3) = 16 (=) 2x(2x-3) + 2x = 16 (=) 4x^2 + 2x = 16 (=) 4x^2 +2x = 16 (=) 4.x.x + 2.x = 16 (=) x(4x+2) = 16 x = 16 V 4x + 2 = 16 x = 16 V 4x = 16-2x = 16 V 4x = 14 x = 16 V x = 14/4 x = 16 V x = 7/2 Rafael Valente 9ºA2
10.1) +- 3
ResponderEliminar10.2) +- 13
10.3) +- -25/4
Wilson Silva 9ºA2
10.1-
ResponderEliminar(x-3)^2 + 3 = 3(7-2x)
(=) x^2 + 2(x-3) + (-3)^2
(=) x^2 -6x + 9 + 3 = 3(7-2x)
(=) x^2 -6x + 9 + 3 = 21-6x
(=) x^2 = 21-9-3
(=) x^2 = 9
(=) x = +/- V9
(=) x = +/- 3 V -3
10.2
x(x-3)/2 = -x
(=) x(x-3) = 2(-x)
(=) x^2 -3x = -2x
(=) x^2 = -2x + 3x
(=) x^2 = 1
(=) x = +/- V1
(=) x = +/- 1 V -1
10.3
(2x + 3) (2x - 3) = 16
(=) 2x(2x-3) + 2x = 16
(=) 4x^2 + 2x = 16
(=) 4x^2 +2x = 16
(=) 4.x.x + 2.x = 16
(=) x(4x+2) = 16
x = 16 V 4x + 2 = 16
x = 16 V 4x = 16-2
x = 16 V 4x = 14
x = 16 V x = 14/4
x = 16 V x = 7/2
Rafael Valente
9ºA2