If the zoo had 30 giraffes and loaned7 giraffes, the number of giraffes that remained at the Zoo is calculated as the subtraction of 7 from 30. So, the equation is:
x = 30 - 7
Where R is the number of giraffes that remained. Then, solving the equation:
R = 30 - 7
R = 23
Answer: equation: 30 - 7
Giraffes remained: 23