7 ● y + 27÷ 9 (._. im horrible at math my bad)​

21 + y

Step-by-step explanation:

lol

Step-by-step explanation:

Ithink it is d because if p=s1t-s2t then you just need to put it together backwards. and because it is a s1t and s2t are both multiples ,and you are trying to find what t is you will need to put t as the total and then divide p by s1 and s2. which this eliminates answers a and b, this will leave you c and d. so then compare both answers c and d, and since you are writing the equation backwards that will leave you only one answer which is d. so i believe that the correct answer is d.