Question

Resolva as equações a seguir: a)18x - 43 = 65 b) 23x - 16 = 14 - 17x c) 10y - 5 (1 + y) = 3 (2y - 2) - 20 d) x(x + 4) + x(x + 2) = 2x2 + 12

Answer 1

a) 18x - 43 = 65

= 18x = 65 + 43

= 18x = 108

= x = 108/18

= x = 6

b) 23x - 16 = 14 - 17x

= 23x + 17x = 14 + 16

= 40x = 30

= x = 30/40

= x = 0,75

c) 10y - 5 ( 1 + y ) = 3 ( 2y - 2 ) - 20

= 10y - 5 - 5y = 6y - 6 - 20

= 5y - 5 = 6y - 26

= 5y - 6y = - 26 + 5

= - y = - 21 ( multiplicar ambos por - 1 )

= y = 21

d) x ( x + 4 ) + x ( x + 2 ) = 2x² + 12

= x² + 4x + x² + 2x = 2x² + 12

= 2x² + 6x = 2x² + 12

= 6x = 12

= x = 12/6

= x = 2