2/3 m+ 3/5 n−r − 1/3 m− 7/10 n+ 1/2 r + m+ 3/4 r− 1/2 n

Question

What does this equal?

Answer 1

First of all we group like terms together:

⅔m-⅓m+m + ⅗n-⁷⁄₁₀n-½n - r+½r+¾r

Now work out how many m, n and r there are.

m: (⅔-⅓+1)m=⁴⁄₃m

n: (⅗-⁷⁄₁₀-½)n is (⁶⁄₁₀-⁷⁄₁₀-⁵⁄₁₀)n=-⁶⁄₁₀n=-⅗n

r: (-1+½+¾)r=¼r

Now add these together to get the answer: ⁴⁄₃m-⅗n+¼r