The sum of two numbers is 51. if one fourth of one number exceeds one fifth of another number by 6, which of the following is the smaller number?

Let x = 1st number and y = 2nd number
Using the sentences:
The sum of two numbers is 51:  x + y = 51
one fourth of one number exceeds one fifth of another number by 6:
(1/4)x > (1/5)y + 6

This means y is the smaller number.
From x + y = 51 → x = 51 - y
Plug into the inequality
(1/4)(51 - y) > (1/5) y + 6
Multiply each side by 20
5(51 - y) > 4y + 120
251 - 5y > 4y + 120 
-9y > -131
y < 

(-14+3/2b) - (1+8/2b) = -5 -5/2b(-10+b) + (7b-5) = 8b-15(7/2b-3) - (8+6b) = -5/2b-11(5+2b) + (2b+3/2) = 4b+ 13/2