We need to convert the folloowing in algebraic terms:
"x is 0.28 of y"
The word "of" normally translates as a multiplication in math terms. Also the words "is" or "was" or "becomes" get translated via the equal sign: "="
So we write:
x = 0.28 * y
where the symbol * I am using to denote multiplication.
The expression: "p is smaller than s by 40"
Means that p is the smaller number. And that s is the largest with a difference between them of 40 units.
That is going to be translated in algebraic words as:
p = s - 40