Keplers third law I understand.

Question

T^2/a^3 of one planet = T^2/a^3 second planet.

But I can't do the algebra to solve for the second planet's a^3 (semimajor axis)

Would someone walk me through the steps please? Thanks.

Answer 1

a2^3= (T2/t1)^2 * a1^3

where a2 is the semimajor axis of the second planet.

Answer 2

Thanks