Question

1) Resolver cada uma das equações seguintes:
a) 5(3x – 1) – 4(2 – 4x) = 2(x – 4) b) 2x² + x.(x + 2) – (x + 3).(x – 3) = 2.(x + 1)²

Answer 1

$a) \\ \\ 5(3x - 1) - 4(2 - 4x) = 2(x - 4) \\ \\ 15x - 5 + 16x - 8 = 2x - 8 \\ \\31x - 13 = 2x - 8 \\ \\ 31x - 2x = -8 + 13 \\ \\ 29x = 5 \\ \\ x = \dfrac{5}{29}$

===

$b) \\ \\ 2x^2 + x.(x + 2) - (x + 3).(x -3) = 2.(x + 1)^2 \\ \\2x^2 + x^2 + 2x - x^2 - 9 = 2(x^2 + 2x + 1) \\ \\ 2x^2 + x^2 - x^2 + 2x + 9 = 2x^2 +4x + 2 \\ \\ 2x^2 + 2x + 9 = 2x^2 + 4x + 2 \\ \\ 2x^2 + 2x - 2x^2 - 4x = -9 + 2 \\ \\ -2x = -7 \ . (-1)\\ \\ =\ \textgreater \ x = -\dfrac{7}{2}$