Why did faraday use two separate laws to explain his concept and didn't just combine both of these into a single statement?

Faraday's first law only tells us if the EMF is induced or not. Unlike the second law, it doesn't have any connection with the EMF's magnitude or direction. Therefore, only the second law of faraday has a formula since it is used to calculate both the magnitude and direction of the induced EMF.

The actual role of these laws is that faraday's law tells us the magnitude of induced EMF and Lenz's law was a modification of faraday which also could tell the direction of induced EMF. These two laws are combined together to form the base of any concept related to electromagnetic induction.

$V=\frac{-d?}{dt}=-\left(15t^2+8t+2\right)$

at t = 2 sec, V = - (15 × 4 + 8 × 2 + 2)

 = 78 V

$I=\frac{V}{R}=\frac{78}{5}=15.6A$

E = -dφ/dt = - (20t + 20) mV.
At t=5s, E = - (100+20) = -120mV.
I = |E|/R = 120mV/2Ω = 60mA.

Using faraday's law magnetic field should be outward and decreasing with time