Two forces whose magnitude are in the ratio 3 :5 gives resultant of 28. If the angle of their inclination is 60 °find the magnitude of each force

Answer 1

(3x)^2 + (5x)^2 - 2(3x)(5x)cos120° = 28
9x^2 + 25x^2 +15x^2 = 28^2
x = 4

So, the two forces are 12 and 20

check:
<12,0> + <10,10√3> = <22,10√3>
magnitude is 28

Answer 2

Not understandable
How is value of x came ???