Will x + 1/2 = x - 1/2 be always true or never true?

Find two rational expressions that have the difference of 2-n/n-4

Carley bought a jacket that was discounted 10% off the original price. the expression below represents the discounted price in dollars, based on x, the original price of the jacket.

Carmen ayer en el mercado compro 3/4 kg de guayabas, 6/8 kg de peras, 1/2 kg de naranjas ¿cuantos kilogramos de fruta compro?