Can someone please!!!! help me with this problem on antiderivatives

Question

Find the particular antiderivative of the following derivative that satisfies the given condition.

dx/dx= 5e^t -4; x(0)=4

Answer 1

x(t) = 5 * exp(t) - 4t + k <--- this is the anti-derivative

x(0) = 4 ---> 4 = 5*exp(0) - 4(0) + k

4 = 5*1 - 0 + k

4 = 5 + k

k = -1

x(t) = 5 * exp(t) - 4t - 1