Final answer:
To find the lifespan of an elephant when a horse's lifespan is 30 years and an elephant lives 56 years longer, we solve the equation E = H + 56, where H is 30 years for a horse, resulting in an elephant's lifespan of 86 years.
Step-by-step explanation:
The question requires us to write a subtraction equation that represents the lifespan of a horse and an elephant, and then solve for the lifespan of an elephant. If a horse's lifespan is 30 years and an elephant's lifespan is 56 years more, we can use the following equation where E represents the elephant's lifespan:
E = H + 56
Since we're given that the horse's lifespan (H) is 30 years, we can substitute 30 for H in the equation:
E = 30 + 56
Therefore, by solving the addition, we get:
E = 86
Thus, an elephant's lifespan is 86 years.