x+4= 12÷3

x+4=4

x=4-4

x=0

÷ (x+16.84) =1/5 (one fifth)

x+ 16.84=5×5

x+ 16.84=25

x=25- 16.84

x=8. 16

x-3/5x=8/ 15

Multiply it by 15 and you get:

15x-9x=8

6x=8

x=8/6

x=4/3

x÷7/5=8/7

x=8/7×7/5

x=8/5

3/4x+ 1/2=7/ 12

Multiply it by 12 and you get:

9x+6=7

9x=7-6

9x= 1

x= 1/9