How to find the value of the variable in 5/x = x/15 ?

Answer 1

You can write this problem as a proportion and solve for x using cross products:

5 = x

x 15

Then:

5 • 15 = x • x

75 = x²

√75 = x

√ 75 = ± 8.66

The variable x can be 8.66 or - 8.66

You could also write √75 as ± 5√3