The answer is 3 ! 3 times three equals 9
Let's named variables as M,J and R
The equation is M+J+R=74
We will represent M with J => M=J+6 and R=2J
when we replace in the equation we get
J+6+J+2J=74 => 4J=74-6 => 4J=68 => J=68/4 = 17
J=17 => M=6+17 => M=23 and R=2* 17 => R=34
Final answer is
Juan served 17 orders
Melissa served 23 orders and
Rafael served 34 orders
Good luck!!!!
5 billion * ( 1 + 0.013 ) ^x = 10 billion
1.013 ^x = 10 : 5 = 2

x = 54
1986 + 54 = 2040
In the year 2040 the world`s population will be 10 billion.