Final answer:
To solve the equation 40 + 30e^(-0.2x) = 50 for x, divide both sides by 30, take the natural logarithm of both sides, and solve for x.
Step-by-step explanation:
To solve the equation 40 + 30e^(-0.2x) = 50 for x, we need to isolate the term with the exponential function. First, subtract 40 from both sides of the equation to get 30e^(-0.2x) = 10. Then, divide both sides by 30 to get e^(-0.2x) = 10/30. Taking the natural logarithm of both sides gives -0.2x = ln(10/30), and finally, divide by -0.2 to find x = ln(10/30)/-0.2 ≈ 2.41 minutes.