It's a bit hard to understand your question; I assume you mean a quarter of the difference between a number and 7. Let's call that number x, then the algebraic expression is
1/4 |x - 7|
Where the | symbols represent the absolute value or modulus of the expression between them, which always gives you a positive number. Imagine the 1/4 is written with the 1 over 4 like it would usually be. For x = 3, you get 1.
Otherwise if you want to allow negatives, you can say
1/4 (x - 7)
which for x = 3 gives you -1.
x-7
(x/7)2
n + 7
(b - 7) should do it.
n+37
x-7
7/ 3/
This expression would be 3x-7.
(x/7)2
n + 7
(b - 7) should do it.
7x + 2
3x + 7
n+37
x / (2y - 7)
x to the third power plus 7
157/10 + xor15.7 + x