Based off of my understanding, it doesn’t have a y intercept, so it should just be
y = 30x.
4(x+2) , 2(2x+4) , 8+4x , 1/2(8x+16) are all the same as 4x+ 8.
The maturity value is the principal value together with interest due.
.. mv = P +Prt
.. = 5350*(1 +0.085*120/360) . . . . . . year is 360 days for "ordinary interest"
.. ≈ 5501.58
The maturity value is $5501.58.