Answer:
16. 3
17. 12 / 7
18. 24 / 5 ( or ) 4.8
Step-by-step explanation:
16.
2 / ( x - 1 ) = 1
2 = x - 1
x = 2 + 1
x = 3
17.
( x / 3 ) + ( x / 4 ) = 1
LCM ( 3, 4 ) = 12
x / 3 = 4x / 12
x / 4 = 3x / 12
( x / 3 ) + ( x / 4 ) = 1
( 4x / 12 ) + ( 3x + 12 ) = 1
( 4x + 3x ) / 12 = 1
7x / 12 = 1
7x = 12
x = 12 / 7
18.
( x / 3 ) + ( x / 2 ) = 4
LCM ( 3, 2 ) = 6
x / 3 = 2x / 6
x / 2 = 3x / 6
( x / 3 ) + ( x / 2 ) = 4
( 2x / 6 ) + ( 3x / 6 ) = 4
( 2x + 3x ) / 6 = 4
5x / 6 = 4
5x = 24
x = 24 / 5
( or )
x = 4.8