1. 11+(-4)=7?
2. -3/5 + (8/35 )=2/8?
Your first answer is correct. Please try again on your second problem. Remember, you need a common denominator when adding or subtracting fractions.
little confused on how to work this one got any suggestions?
Yes. First, what is the common denominator?
Nope. 5 is the greatest common factor; it is not the least common denominator.
Study this site for common denominators.
http://www.mathsisfun.com/numbers/common-denominator.html
175?
or would it have been 145/175?
Isn't 35 evenly divisible by both 5 and 35?
The common denominator is 35.
Please go back and study the website I posted for you.