Answer:
Step-by-step explanation:
The total charge ("total" is a clue word!) is the standard charge plus the insurance charge.
[tex]C=S+I\\C=(0.4M+17.75)+(0.15M+4.90)\\C=0.55M+22.65[/tex]
That last step comes from combining like terms (put the M's together and the "just numbers" together).
