What is added to 5,9,17,27 to be in proportion

Answer 1

( 5 + x ) / ( 9 + x ) = ( 17 + x ) / ( 27 + x )

( 5 + x ) * ( 27 + x ) = ( 17 + x ) * ( 9 + x )

x ^ 2 + 32 x + 135 = x ^ 2 + 26 x + 153

32 x - 26 x = 153 - 135

6 x = 18

x = 3

( 5 + x ) / ( 9 + x ) = ( 17 + x ) / ( 27 + x )

( 5 + 3 ) / ( 9 + 3 ) = ( 17 + 3 ) / ( 27 + 3 )

8 / 12 = 20 / 30

4 * 2 / 4 * 3 = 10 * 2 / 10 * 3

2 / 3 = 2 / 3