Let me answer those two questions in the reverse order.
1). How it can be solved:
7x + 5 = 3x - 11
Subtract 3x
from each side: 4x + 5 = - 11
Subtract 5
from each side: 4x = - 16
Divide each side
by 4 : x = - 4
2). The answer is x = - 4 .
-4 is called the 'solution' to the equation, because that's the number
that 'X' MUST be. If it's any other number, then the equation is not
a true statement.
LINEAR because it follows the format y=mx+b and does not contain any exponents
142 houses can be built
71/2 reduces to 35.5
35.5/.25 = 142