Hooke's Law with Series Springs

[maulucci]

Homework Statement

The problem is in the attachment

Homework Equations

F=-kx
k1x1=k2x1

The Attempt at a Solution

I got as my answer Keq= (k1k2)/(k1+k2)

i just wanted to see if i had the right idea or no.

 

[Simon Bridge]

Welcome to PF;

i just wanted to see if i had the right idea or no.

... then you need to tell us the idea and not just the final result you got ;)

 

[maulucci]

-k1x1=-k2x2=F
F=-keq*x
solving for x1
x1=[(k2)/(k1+k2)] +x2
putting into F=-k2x2+k2x1
F=x2 (-k1k2-k2^2+k2^2)/(k1+k2)
simplified
F=-[(k1k2)/(k1+k2)]*x2

then the Keq = (k1k2)/(k1+k2) ?