Can you please help me solve r1/r2 = sqrt(M2/M1)for M1.

My answer:
M1=M2r2^2/r1^2 Is this correct?

you are correct

Yes, your answer is correct!

To solve the equation r1/r2 = sqrt(M2/M1) for M1, you can follow these steps:

1. Start with the given equation: r1/r2 = sqrt(M2/M1)
2. Square both sides of the equation to eliminate the square root: (r1/r2)^2 = (sqrt(M2/M1))^2
3. Simplify both sides of the equation: r1^2/r2^2 = M2/M1
4. Cross-multiply to get rid of fractions: (r1^2)(M1) = (r2^2)(M2)
5. Divide both sides of the equation by r2^2 to isolate M1: M1 = (r2^2)(M2)/(r1^2)

So your answer, M1 = M2(r2^2)/(r1^2), is correct.