Answer:
z is equal to 18.5
Step-by-step explanation:
When an equation is in the format a/b = c/d, the quickest way to simplify it is to cross multiply. Each side is multiplied by the other sides denominator, eliminating the division:

So z is equal to 18.5
The answer is 12.
Steps
If that number is x
(3+x)/(8+x)=3/4
"Cross multply"
4(3+x)=3(8+x)
12+4x=24+3x
x=12
To check: add 12 to 3 and 8. 3+12=15 and 8+12=20. 15/20=3/4
Answer:
6.83333333333 (repeated)
Step-by-step explanation:
1/3 x 20.5= 6.83333333333...