Let f(x)=8x+1-15e^x. Then the equation of the tangent line to the graph of f(x) at the point (0,-14) is given by y=mx+b.

The slope at any point is given by the derivative of the function  =

8 - 15e^x

So at x = 0  , the slope is   8 - 15e^0   =  -7  = m         and  b = -14

And the equation of the tangent line  is

y = -7x -  14

Here's the graph with the tangent line  ...  https://www.desmos.com/calculator/zw5yhfi2ar