a + b/3 - b - 2a/5
= -7a/5 + b/3
Now, to write this expression as a single fraction in its lowest form, we need to find the least common multiple (LCM) of the denominators of the two fractions. The LCM of 3 and 5 is 15.
Multiplying the first fraction by 5/5 and the second fraction by 3/3, we get:
(-7a/5) x (3/3) + (b/3) x (5/5)
= -21a/15 + 5b/15
= (-21a + 5b)/15
I hope that helps you.
