All you need is in the photo

please explain step by step

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?

Plz hurry evaluate the expression a+b where a=8 and b=19

Anumber is equal to twice a smaller number plus 3. the same number is equal to twuce the sum of the smaller number and 1. how many solutions are possible for this situation