What have you tried so far?
The tangent is simply the value of the derivative at x=1. So first you have to know if the function y=-2x^5+7 is derivable at x=1 . If it is it should yield the value of the tangent.
So it should be something like the tangent at a point let's say x0 is simply f'(x0).
Now the OP can show some effort before we give any more guidance.