Answer:
-5 cm
Explanation:
We can use the lens equation:
[tex]\frac{1}{f}=\frac{1}{p}+\frac{1}{q}[/tex]
where
f = -7 cm is the focal lenght
p = 14 cm is the distance of the object from the lens
q is the distance of the image from the lens
Solving the equation for q, we find
[tex]\frac{1}{q}=\frac{1}{f}-\frac{1}{p}=\frac{1}{-7 cm}-\frac{1}{14 cm}=-\frac{3}{14 cm}\\q=\frac{-14 cm}{3}=-4.67 cm \sim -5 cm[/tex]