Читать книгу Algebra I All-in-One For Dummies - Mary Jane Sterling, Mary Sterling Jane - Страница 31

Algebra involves symbols, such as variables and operation signs, which are the tools that you can use to make algebraic expressions more usable and readable. These things go hand in hand with simplifying, factoring, and solving problems, which are easier to solve if broken down into basic parts. Using symbols is actually much easier than wading through a bunch of words.

 To simplify means to combine all that can be combined, using allowable operations, to cut down on the number of terms, and to put an expression in an easily understandable form.

 To factor means to change two or more terms to just one term using multiplication. (See Chapters 11 through 13 for more on factoring.)

 To solve means to find the answer. In algebra, it means to figure out what the variable stands for. You solve for the variable to create a statement that is true. (You see solving equations and inequalities in Chapters 14 through 19.)

 To check your answer means to replace the variable with the number or numbers you have found when solving an equation or inequality, and show that the statement is true.

Q. Simplify the expression:

A. You can add the two numbers. Simplified, you get . You see all the types of simplifying methods in Chapter 7.

Q. Factor the expression:

A. The two terms have a common factor of 5. Make this one term by taking out the common factor and writing it times the sum of the remaining factors. This can be or, simplifying, it’s . Factoring methods are found in Chapters 11 through 13.

Q. Solve the equation for the value of x: .

A. The only number that will make this equation a true statement is the number 3. So . Solving equations is covered in Chapters 14 through 18.

Q. Check to see if it’s true that in the equation .

A. Replace the x in the equation and simplify on the left. You have , which is the same as or . Yes, this is the solution to the equation.

23 Simplify the expression .

24 Factor the expression .

25 Solve for the value of z in the equation .

26 Check to see if both and 3 are solutions to the equation .