Answer:
767 houses
Step-by-step explanation:
Initially there are 3212 houses in the city.
After the boom there are 3979 houses in the city.(due to boom there is an increase in the number of houses).
The number of houses developed by the developers is the difference between the number of houses before and after the boom.
The number of houses developed=3979-3212=767 houses
5 : 5, 10, 15, 20, 25
6 : 6, 12, 18, 24, 30
-4(x-7)=36
-4x+28=36
-4x=8
x=-2
2x-5 is the expression that represents 5 less than twice x
