Posted by charlie on .
Keplers third law I understand.
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.

Physics/Maths 
bobpursley,
a2^3= (T2/t1)^2 * a1^3
where a2 is the semimajor axis of the second planet. 
Physics/Maths 
charlie,
Thanks