Resposta :
seria assim x + 3 + r = 4x - 2 => r = 3x - 5
4x - 2 + r = 7x - 7 = x - 1 => 6x = 6 => x = 1
x = 1 => {4, 2, 0}
4x - 2 + r = 7x - 7 = x - 1 => 6x = 6 => x = 1
x = 1 => {4, 2, 0}