3. 5mn ( 2m + 6n + 1 )
4. 4a^3b^2c ( 18a^2b - 8c )
5. (X-15)(X+15)
6. -4(y-4.5)(y+4.5)
8. 2X(X-10)(X+10)
i am not sure if no. 8 is right
This answer is c (x-4)(x+4)
The answer is 6. 15 triples with 9 and 12
So to set up this equation, you have to do
Time1*Workers1=Time2*Workers2
In this case, Time1=24 days, Workers1=15 electricians, and Workers2=18 electricians, and we have to solve for Time2
Thus we get 15*24=18*Time2
Time2=15*24/18=20 days
