Good evening Brainiac
4/5m^2 = 9/m + 2/10m
4/5mm = 9/m + 2/10m
Now we should multiply all terms by mm and cancel
So we'll have
4/5 = 9m+2m/10
4/5 = 46/5 m
Now flip the equation so we can feel more comfortable with the side
46/5 m = 4/5
m= 2/23
I hope that's help:)