26x=74 which describe how to solve the equation below

Which addition property is being illustrated below? (type commutative or associative) (6 + 7) + 1 = 6 + (7 + 1)

The function f(x) = 14,600(1.1)* represents the population of a town x years after it was established. what was the original population of the town?

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?