Resuelve las sumas y restas con distintos denominador, calculando el m. c.m. a) 7/4+5/6+1/3= b) 3/5-1/2+1/4= c) 3/8+5/6= d) 7/9+3/4-1/3= e) 5/7-3/4= Porfa es para el lunes

Sanderson is having trouble with his assignment. his shown work is as follows: − 3 7 7 3 = − 3 7 × 7 3 = − 21 21 = −1 however, his answer does not match the answer that his teacher gives him. complete the description of sanderson's mistake. find the correct answer.