Answer:
144
Step-by-step explanation:
(81 - 9) * 2 = 144
work backwards, you now have 81 books. But you bought 9, so pretend you didn't buy the 9, means you would have 9 less books. so 81-9.
Then you multiply by 2 because originally you sold half of the books, so before you sold half, you had double the amount, so you multiply that by 2.
First, substitute the values of the variables into the equation:
2x+(3)(6)=36
Then, you must simplify,
2x+18=36
Then, you must factor out 18 to leave x and its coefficient alone on one side of the equation:
2x+18-18=36-18
Then you must simplify the equation and divide by 2 on both sides of the equation to factor out the coefficient:
2x/2=18/2
Then you will simplify and you will find the value of x:
x=9
You want to find out how many cups of flour Jaylin needs to make 30 biscuits.
We currently know 2 cups of flour makes 20 biscuits.
We can halve the recipe down to make it simplier - simply divide all ingredients by 2 to halve it.
1 cup of flour = 10 biscuits
Since 1 cup of flour equals 10 biscuits, and 2 cups of flour equals 20 biscuits, we can safely say 3 cups of flour equals 30 biscuits.
Answer:
120
Step-by-step explanation:
Here there are 10 different packages in which we have to choose 3
so required number of ways 
So there are 120 ways in which we select the different groups of software package.
so the correct answer will be 120
