the average lifespan of a tiger is 17 years. this is 3 years less than the average lifespan of a lion. write and solve an equation to find the average lifespan of a lion.

The average life span of a lion is 20 years.

Step-by-step explanation: If I understand correctly your question is pretty much saying that the 17 year life span of a tiger plus 3 years equals the life span of a lion. So 17 plus 3 equals 20 years. another way of putting it is that the average life span of a lion is 3 years more than the 17 year life span of a tiger. 17+3=20 Or x-3=17 to get rid of the - 3 we have to add a positive 3 to both sides (x-3+3 = 17+3) = x=20

x=y-3

20 years

Step-by-step explanation:

So lets make some variables to equate them, let x be the lifespan of the tiger and y be the lifespan of a lion. Since the lifespan of a tiger if 3 years less then a lifespan of a lion, lets subtract the 3 year difference from the lifespan of a lion.

x=y-3

Lets input the known lifespan of a tiger.

17=y-3

Add 3 to both sides to get our variable on its own.

17+3=y-3+3

do the addition

20=y

The lifespan of a lion is 20 years.