Question 1179570
<br>
One very formal method: Use the given parameters to determine the value of the constant K and then use that constant with the one new parameter to determine the other new parameter.<br>
P=K/V
100=K/4
400=K<br>
P=K/V
P=400/45 = 80/9<br>
For inverse variation, I think a problem is more easily solved by rewriting the formula as<br>
PV=K<br>
In that form, the relation says that the product of the pressure and the volume is a constant.  So the path to the answer to the problem is shorter:<br>
100(4)=P(45)
P=400/45 = 80/9<br>