1. Microscope magnification
And you

2. Double magnification (M by 2 lenses)
Please make the following diagram
Like so….

3. Eyepiece lens
Objective lens
you
object
The (real) image from lens 1, serves
As the object for the second lens
Notice how the final image is inverted relative to the object
Total Magnification = (M1)(M2)

4. What is the magnification here?
Eyepiece lens
Objective lens
6 cm
3 cm
= di(1)
= do(2)
4 cm
= do(1)
17 cm
= di(2)

5. The key man… M1 = -di(1) /do(1) = - 6/4 = - 1.5
Mtot = (M1)(M2) = (-1.5)(5.6666) = - 8.5
Notice the negative value just indicates the end image is inverted relative to the initial object

6. Overall magnification due to (ma)(mb)
Image formed by one lens serves as object for second lens
Ma = -dia/doa Mb= -dib/dob
Mtot = (-dia/doa)(-dib/dob)