5/3 + (-7/5) = ?
We want to set the denominators as equal, so we should common denominators. A low common denominator in this question is 15, so 5/3 should be multiplied by 5 because the denominator (3) is 5 times less than 15. (-7/5) is 3 times less than 15 so we mulitply it by 3. (5/3)*5= 25/3. (-7/5)*3=(-21/3). so now we have 25/3 - 21/3. we leave the denominators alone and work with the numerator first. so 25-21=4, now put the denominator and we get 4/3