Evaluate the definite integral. 1 3ti + 7t3j + 3 t k dt −1

It would be so much clearer if you'd please put parentheses around the t-functions: 

Evaluate the definite integral. (1/3)t i + (7t)^3 j + (3t) k dt

Also , there should be a set of brackets or parentheses around

(1/3)t i + (7t)^3 j + (3t) k.  And, finally, we need an explanation of your  âˆ’1.  I do not recognize it at all.

To find the indefinite integral of  [ (1/3)t i + (7t^3) j + (3t) k ]dt
integrate term by term:

(1/3)(t^2)/2) i + 7*t^4/3 j + (3*t^2/2) k + c

The missing factor is (81-25^2)=(9-5x)(9+5x)