hookes law gives the equation F=kx where F is the elastic force and k is the constant and x or small e is extension if we draw a graph you'll see that the graph increases by the same ratio every single time hence giving a straight line show that they are F and x are propotional to a certain limit
the answer is 3
but a way to work these problems out is to use PEMDAS
p-parentheses
e-exponent
m-multiplication
d-division
a-addition
s-subtraction
they have to be donr in that order or the answer will come out different
120^ is the answer for this problem