Expanding and simplifying brackets

It seems that there may be a mistake in the book's answer. In summary, the conversation discusses a problem with finding the correct answer for a given mathematical expression. The person asking for help has correctly expanded and simplified the expression, but the answer given in the book is different. It is possible that there is a mistake in the book's answer.
  • #1
Gringo123
141
0
Could someone please expain where I went wrong with this?

expand and simplify the following:
1/8(6x - 12y) + 1/2(3x + 2y)

I expanded the brackets like this:
0.75x - 1.5y + 1.5x + y

and simplified like this:
2.25x - 0.5y

But the right answer is: 2.25x - 2.5y
 
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  • #2
Your answer is correct for the problem you showed. Are you sure you copied the problem correctly? If so, the "right" answer is wrong.
 
  • #3
Thanks Mark.
There must have been a misprint on the answer page of my book.
I have the same problem with this one.

1/5(15x + 10y) + 3/10(5x - 5y)

My answer is: 4.5x + 0.5y

The book says it should be: 4.5x -0.5y

Have I made a mistake or is the book wrong again?
Thanks once again for your help.
 
  • #4
Assuming you have written the problem as it appears in the book, your answer is correct.
 

FAQ: Expanding and simplifying brackets

What is the purpose of expanding and simplifying brackets?

The purpose of expanding and simplifying brackets is to simplify algebraic expressions and make them easier to solve or manipulate. This process involves distributing the terms inside the brackets to the terms outside the brackets and combining like terms.

What are the basic rules for expanding and simplifying brackets?

The basic rules for expanding and simplifying brackets are the distributive law, which states that multiplying a sum by a number is the same as multiplying each addend by the number and then adding the products, and the commutative and associative properties, which allow us to rearrange and regroup terms to simplify the expression.

How do you expand brackets with multiple terms?

To expand brackets with multiple terms, you need to distribute each term inside the brackets to every term outside the brackets. This means multiplying each term inside the brackets by each term outside the brackets and then combining like terms. It is important to follow the order of operations and use the distributive law to simplify the expression.

What is the difference between expanding and simplifying brackets?

Expanding brackets involves multiplying the terms inside the brackets to the terms outside the brackets, while simplifying brackets involves combining like terms to reduce the expression into a simpler form. Expanding is the first step in simplifying, and both processes are used to make algebraic expressions easier to solve or manipulate.

Why is expanding and simplifying brackets important in mathematics?

Expanding and simplifying brackets is important in mathematics because it allows us to solve complex algebraic expressions, simplify equations, and solve real-world problems. It is also a fundamental concept in algebra and is used in advanced math subjects such as calculus and linear algebra.

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