Answer:
(6x+3)(6x-3)
Step-by-step explanation:
I used FOIL
Multiply the first numbers 6x*6x=36x^2
The outer -18x
Inner 18x which the outer and the inner cross out
Last 3*-3=-9
36x^2 -9
Answer:
250
Step-by-step explanation:
Number of labourers * Number of days worked = Total number of working days
Total number of working days to construct a 4km long road: 
Total mumber of working days to construct a 8km long road: 
Labourers: 20000 ÷ 80 = 250.
250 labourers are required.