Answer: See explanation
Step-by-step explanation:
Let the number of regular trucks be a
Let the number of dually trucks be b.
From the question,
a + b = 73 .......... i
4a + 6b = 354 .......... ii
Multiply equation i by 4
Multiply equation ii by 1
4a + 4b = 292 ........ iii
4a + 6b = 354 ........ iv
Subtract iii from iv
2b = 62
b = 62/2
b = 31
The number of dually trucks = 31
Since a + b = 73
a + 31 = 73
a = 73 - 31
a = 42
The number of regular trucks = 42