Part A: For 100 miles, the cost will be same for both companies.
Part B: Alex should use Drive and Move company as it will cost him less money.
Step-by-step explanation:
Given,
Starting amount of YMI= $40
Per mile charges = $1.99
Let,
x be the number of miles.
y be the total charges.
y = 1.99x+40 Eqn 1
Starting amount of DM = $60
Per mile charges = $1.79
y=1.79x+60 Eqn 2
Part A:
For same charges;
Eqn 1 = Eqn 2

Dividing both sides by 0.20

For 100 miles, the cost will be same for both companies.
Part B:
Total miles = x = 150
Putting x=150 in Eqn 1
y=1.99(150)+40
y=298.5+40
y=$338.50
Putting x=150 in Eqn 2
y=1.79(150)+60
y=268.5+60
y=$328.50
Alex should use Drive and Move company as it will cost him less money.