Using a system of equations, the expression or the number of touchdowns he scored in his second year is: 2(t - 1)
A system of equations is when two or more variables are related, and equations are built to find the values of each variable.
In his first year, he scored t touchdowns. In the second, the amount was two less than twice the number of touchdowns he scored in his rookie year, hence the expression is:
2t - 2 = 2(t - 1)
More can be learned about a system of equations at https://brainly.com/question/24342899