1. 2a=9b first we will divide the both sides with parameter b and get
2(a/b)=9 now we will divide both sides with number 2 and get
a/b=9/2 => a : b = 9 : 2
2. 6a-3b=5b first we will add to both sides number (+3) and get
6a=5b+3b => 6a=8b then divide the both sides with parameter b and get
6(a/b)=8 now we will divide the both sides with number 6 and get
a/b=8/6 if we simplify the fraction we get
a/b=4/3 => a : b = 4 : 3
3. a+b=3b we will add to the both sides parameter (-b) and get
a=3b-b => a=2b then divide the both sides with parameter b and get
a/b=2 => a/b=2/1 => a : b = 2 : 1
4. a/5=b/7 first we will divide the both sides with paremeter b and get
a/(5b)=1/7 now we will multiply the both sides with number 5 and get
a/b=5/7 => a : b = 5 : 7
Good luck!!!
These 4 options are correct.
I suppose a DJ wants to select 4 different songs, then there are: 12*11*10*9 = 11880 ways to choose them.
If the order of the songs he plays doesn't matter, there are: 
ways to choose them.
Answer: 3,885.71428571428571 I’m not sure
Step-by-step explanation:
Answer: The system of equation is,
2 ( x + y ) = 50
x = 2 y - 5
Step-by-step explanation:
Let x represents the length of the rectangular brownie and y represents the width of the rectangular brownie.
Thus, the perimeter of the brownie = 2 ( x + y )
But, According to the question,
Perimeter of the brownie = 50,
2 ( x + y ) = 50
The length of the brownie is 5 less than twice the width,
That is, x = 2 y - 5
Thus, the required system of equation is,
2 ( x + y ) = 50 , x = 2 y - 5
