If you want to know the value of a function, you need to substitute the variable (here n) for the value:
so in the function
9(n+2)−5n
we substitute n with 14:
9(14+2)−514
first calculate the inside of the bracket:
916−514
9 times 16 is 144
144-514
5*14 is 70, so we have
144-70=74
so the answer should actually be 74!
Perhaps you mistyped the questions? can you check it again, please?
