Final answer:
The correct expansion of the equation (s-t)(s/t) is s^2/t - st/t. This is found by distributing each term inside the parentheses by s/t, leading to choice b) s^2/t - st/t as the correct answer.
Step-by-step explanation:
The question seeks the correct expanded version of the equation (s-t)(s/t). To expand this equation, we need to distribute the terms inside the first parentheses by the term outside, which in this case is (s/t). Here is a step-by-step explanation:
1. Multiply s by (s/t).
2. Multiply -t by (s/t).
By performing these multiplications, we get the first term as s2/t and the second term as -st/t, because in the second multiplication, -t and t in the denominator cancel out, leaving us with just -s.
The complete expanded formula is:
s
2
/t - st/t
Therefore, the correct choice is b) s2/t - st/t.