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Algebra for Adults:
Part 9, First Review:
Post Date:

Before we review, here are the teasers from Part 8.

What are the terms of these expressions?

7 + 3x - 2(4 + 3)
Terms are 7, 3x, 2(4 + 3)

45x + 3(2 - 4) - 15
Terms are 45x, 3(2 + 4) 15

64 + 23 + 18 - 22
Terms are 64, 23, 18, 22

What are the factors of the following expressions.

a(c + 4)
Factors are a, (c + 4)

9ab
Factors are 9, a, b

2(x - c)(y + 13)
Factors are 2, (x - c), (y + 13)

What are the base, exponent, and power of the following.


Base = 12, exponent = 2, power = 144


Base = 4, exponent = 3, power = 64


Base = 2, exponent = 8, power = 256

Combine the following terms:

27 z+ 3 z = 30z

2(a + b) + 6(a + b) = 8(a + b)

Now, we can review:

In arithmetic, we found there were just four basic operations to consider. These being, __________________________________________________________.

The other things we studied, Fractions, Decimals, and Percents, turned out to be different ways of looking at mathematical situations but the four basic operations applied to all of them.

The big difference in algebra is that we will represent numbers with ___________, namely characters of the alphabet.
This will make any mathematical statement much shorter that its verbal equivalent. In turn, that will make the statement easier to understand and manipulate.

A verbal statement, might be: five times any number plus two times the same number is equal to seven times the number.
Let the letter n stand for the number and write the equivalent algebraic statement.
________________.

In algebra:
When we multiply a number by a letter the ____________________ may be omitted.

The commutative law of addition is:
Interchanging addends does not change their sum.

The Commutative law of multiplication is:
Interchanging factors does not change their ____________.

a + b = c and b + a = c are ________________ statements.

By the commutative law of multiplication, ab = c and ba = c are equivalent statements.

Microsoft Bookshelf gives this definition:

Equation
Mathematics: A statement asserting the equality of two expressions, usually written as a linear array of symbols that are separated into left and right sides and joined by an equal sign.

This shorthand (equation) way of representing mathematical relationships is the big difference between basic mathematics and algebra.

It is important to notice that algebraic expressions need not be complete equations.
For example:

3x is an algebraic expression that means 3 times x.
12/y is an algebraic expression that means _________________.

Division by zero is undefined or impossible in math. This is still true in algebra. In the case of 12/y above where y = 0 the solution is undefined.

Express a weight that is eight times larger than another weight (w).
_________________________.

Express a height that is 3 feet shorter than a height z.
The answer is z - _______________.

Six times the sum of z and y is 6_____________).

Evaluation is a formal math word. It just means finding the answer or solution.

Normally, when the order of evaluation of an expression may not be clear, we use parentheses to make it clear.

The rule is, we always evaluate the part of the expression enclosed in parentheses ______.

Evaluate:
(3 + 4) x 6

Most of the time, we can avoid ambiguity through the use of parentheses.
However, when we encounter an expression without parentheses we have a procedural rule.

To evaluate and expression without parentheses, do the multiplication and division in order from left to right. Then do the addition and subtraction in order from left to right.

 

Evaluate the expression 7(z + y) + 2z - (y +3)/2 where z = 3 and y = 5.

 

 

 

Here are some definitions that are used in algebra.

A term is a number or the product of ____________.

A factor of a term is any of the numbers multiplied to form the ______.

We can have complex factors.
For example:

In cd(a + b), (a + b) is a complex factor.
The factors of this expression are___________________________.

We can also have more than one term in an expression.
For example:
In the expression b + bd - (b - d) the terms are ______________________.

Any factor or group of factors of a term is a coefficient of the product of the remaining terms.

In the expression 6(x + y) 6 is a coefficient of (x + y) and (x + y) is a coefficient of_____.

We have literal coefficients and numerical coefficients.

In the expression 5xy
5 is the numeric coefficient of xy.
______ is the literal coefficient of 5.

In basic math, we learned to raise a number by a power or multiply it by itself a number of times. We indicate that operation with a superscript number.
For example:

Formally:
We call the superscript number the exponent.
We call the number being multiplied the _______.
The result of the operation is called a power of the base.
For example:


125 is the third power of 5.
5 is the base.
3 is the _____________.

In certain case we can combine terms.
We can do this if the terms have identical literal factors and exponents.
For example:

We can combine 8 + 7 + 2 into a single term 17.

It is not quite as obvious when we add literal factors to the mix.
For example:

We can combine 12x + 8x into a single term _______.

If you had trouble with any of the above you may want to review Parts 5 through 8.
Back to Algebra for Adults.

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