Question

A positive number when decreased by 4 is equal to 21 times the reciprocal of this number is

Answer 1

Answer:

Step-by-step explanation:

given that

x-4=21[1/x]

x=21/x+4

x=21+4x/x

x^2=21+4x

x^2-4x-21=0

x^2-7x+3x-21=0

x(x-7)+3(x-7)=0

(x-7)(x+3)=0

x=7,-3