To determine how many windows must a house have for Company A to be less expensive than Company B, we can set up inequalities based on the pricing models of both companies.
Let's denote the number of windows as \( w \).
-
Cost from Company A: This cost is \( 312 + 12w \) (where $312 is the base charge for power-washing the siding and $12 is the cost per window).
-
Cost from Company B: This cost is \( 36w \) (where $36 per window assumes the price includes the siding).
We want to find when Company A's cost is less than Company B's cost:
\[ 312 + 12w < 36w \]
Now, we can solve the inequality:
-
Subtract \( 12w \) from both sides: \[ 312 < 36w - 12w \] \[ 312 < 24w \]
-
Divide both sides by 24: \[ \frac{312}{24} < w \] \[ 13 < w \]
This means \( w > 13 \).
Therefore, the number of windows must be greater than 13 for Company A to be less expensive than Company B. The correct inequality is:
\[ w > 13 \]