Simply a3 • a4
And (2a) (5ab)

Hello i need some with trigonometric substitutions. [tex]\int\limits^a_b {x} \, dx[/tex]

After the seventh month of a 12-month loan: the numerator is: {(n + 11) + (n + 10) + (n + 9) + (n + 8) + (n + 7) + (n + 6) + (n + 5)} = , and the denominator is: {(n) + (n + 1) + + (n + 11)} = . therefore, the fraction is numerator/denominator (to the nearest tenth) = %

Can someone show me step by step how to do this?