Question

in the above attached problem how second step get from first step explain detail​

Answer 1

Explanation:

in the first step the equation formed is in the form of GP

so the sum of the infinite GP = a / (1 - r)

here a = 1 and r = 1/4

thus

the gravitational force will be

G* 1/(1 - 1/4) = 4G/3