Calculus math help please

Question

3. Find the tangent line to  at 

Answer 1

derivative of 7^x = (7^x)(ln7)

derivative of 4e^x = 4e^x

at x= 0

the derivative = f'(0) = (7^0)ln7 + 4e^0 = ln7 + 4

y=(4+ln7)x + b is the tangent line. Solve for b by plugging in (0, 5)

b= 5

y=(4+ln7)x + 5 is the tangent line at x=0, at (0,5)