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Math 96 Test 1
Real numbers & properties Solve equations & inequalities Absolute Value equations & inequalities Translation word problems Exponent Rules Graph linear functions Find equation of a line
Classify the given numbers.
Natural: 1, 2, 3, 4, … also will be whole, integer, rational and
real Whole: 0, 1, 2, 3, …
also will be integer, rational and real Integer: … , -2, -1, 0, 1, 2, …
also will be rational and real Rational: can be written as a fraction – decimals
with repeating or terminating decimals Irrational: decimals with no repeating patterns
and they go forever Real: all the above numbers are real numbers – so far everything you know is a real number!
Classify the given numbers.
-2 0 .4545…
Natural Numbers
Whole Numbers
Integers
Rational Number
Irrational Numbers
Real Numbers
11
Classify the given numbers.
-2 0 .4545…
Natural Numbers
Whole Numbers X
Integers X X
Rational Number X X X
Irrational Numbers X
Real Numbers X X X X
11
Name the properties of Real numbers.
Associative: something new inside the parentheses – add and multiply
Commutative: something has moved its location – add and multiply
Distributive: multiply on the outside, adding in the inside
Identities: “it” will not change – add by zero OR multiply by 1
Inverses: will make “it” go away – add the opposite OR multiply by the reciprocal
Name the properties of Real numbers.
Multiplication Property of ZERO: if you multiply BY zero you get zero!
Multiplication Property of ZERO: a (0) = 0 Closure: you get an answer! a + b = c Trichotomy Property: 1 of 3 things must
be true a < b or a = b or a > b Transitive Property: if a < b and b < c
then a < c
Solve each equation for x.
Step 1. identify the variable you are solving for and clear parentheses
Step 2. clear fractions (multiply by the LCM) and/or clear decimals (multiply by 10s)
Step 3. get just 1 variable Step 4. get the variable alone, furthest first –
according to the reverse Order of Operations
Solve each equation for x.
5[2 – (2x – 4)] = 2(5 – 3x)
5[2 – 2x + 4] = 2(5 – 3x)
5[– 2x + 6] = 2(5 – 3x)
-10x + 30 = 10 – 6x
-4x + 30 = 10
-4x = -20
x = 5
Solve each equation for x. 2 1 1 3
18 4 2
x x
8 2 1 8 1 8 38 1
8 4 2
x x
2 1 2 4 3 8x x
2 1 4 12 8x x
2 3x 3/ 2x
Graph the following Inequalities
Greater than and Less than – open circle Greater than or equal to and Less than or
equal to – closed circle If x comes first – go the same way as the
inequality Space numbers evenly on the number
line, one variable – one line
Solve Inequalities for x, and graph your solution.
IF you multiply (or divide) by a negative, the inequality will change direction.
Follow the rules for graphing inequalities.
Solve this inequality for x, and graph your solution
4 – 7x > -10
-7x > -14
(-1/7)(-7x) < (-1/7)(-14)
x < 2
Multiplied by a Negative
-4 -2 0 2 4 6
Solve for the indicated variable. Step 1. identify the variable you are solving
for and clear parentheses Step 2. clear fractions (multiply by the LCM)
and/or clear decimals (multiply by 10s) Step 3. get just 1 variable, factor if needed Step 4. get the variable alone, furthest first –
according to the reverse order of operations
Solve for the indicated variable.
W = ab + ah; solve for a
Too many a’s – factor!
W = a (b + h)
W = a(b + h) (b + h) (b + h)
W= a
b+h
Solve the following equations containing Absolute Value bars.
Make sure you FIRST isolate the absolute value bars
2 Bars – 2 Problems – what can go into the bars and come out as desired?
Special case: | x | = negative No Solution
Solve the following equation containing Absolute Value bars.
| 2x – 1 | + 5 = 8
| 2x – 1 | = 3
2x – 1 = 3 2x – 1 = -3
2x = 4
x = 2
2x = -2 x = -1
Solve each of the Absolute Value Inequalities and graph.
Make sure you FIRST isolate the absolute value bars
2 Bars – 2 Problems – what can go into the bars and come out as desired?
Special cases: | x | < negative | x | > negative No Solution all real
numbers
Solve the Absolute Value Inequality and graph.
| 4 – 2x | + 5 > 3
| 4 – 2x | > -2
Always True,
Absolute Value is greater than a Negative
Translate these words and write an equation then solve it.
Read the whole problem all the way through at least once.
Write what you read as you read it Sum – (add inside parentheses ) Total – (add inside parentheses ) Difference – (subtract inside parentheses) Less than – write subtraction “backwards” Subtracted from – write subtraction
backwards
Translate these words and write an equation then solve it.
Five times the difference between three
and twice a number is negative five.
Translate these words and write an equation then solve it.
Five times the difference between three
and twice a number is negative five.
5(3 – 2n) = -5
15 – 10n = -5
-10n = -20
n = 2
The number is two! End in Words!
Simplify the given expression. Do not leave negative exponents.
0 1
m n m n
mm n
n
nm mn
a a a
aa
a
a
a a
1
a negative exponent
"means" take the
reciprocal of the base
mm
aa
Simplify the given expression. Do not leave negative exponents.
Clear outside exponents first,
move the “location” of the base that has a negative exponent
the base still has an exponent, but now it is positive.
Simplify the given expression. Do not leave negative exponents.
22 1
5 2
y y
y y
25 2
2 1
y y
y y
10 4
4 2
y y
y y14
122
y
yy
Simplify the given expression. Do not leave negative exponents.
Clear outside exponents first, make sure all parenthesis are “gone” before “moving” bases.
The base is only what the exponent touches.
Simplify the given expression. Do not leave negative exponents.
2
4 3
x y
x y 2 3
4
x yy
x 2 4
4
x y
x 4
2
y
x
Graph by Plotting Points
Use my favorite numbers -2, -1, 0, 1, 2
Replace x with the value you have in the table and find the value of y.
(x, y) a point is an ordered pair of numbers First number, go along the x-axis Second number, go in the y-axis direction
Graph by Plotting Pointsy = ½ x – 5
(-2, )
y = ½ (-2) – 5
y = -6
(-2, -6)
(4, )
y = ½ (4) – 5
y = -3
(4, -3)
Graph by Intercepts
Let x = 0 to find the y-intercept, the point on the y-axis.
Let y = 0 to find the x-intercept, the point on the x-axis.
Graph by Intercepts2x – 4y = -8
2(0) – 4y = -8
-4y = -8
y = 2
(0, 2)
2x – 4(0) = -8
2x = -8
x = -4 (-4, 0)
Graph by using Slope-Intercept form
Solve for y: y = mx + b
b = y-intercept, start on y-axis
from the “starting” point, go up and over
risem
run
Graph by using Slope-Intercept form
3x – 2y = 4
-3x -3x
-2y = -3x + 4
(-½)(-2y) = (-½)(-3x + 4)
y = 3/2 x – 2
Graph the corresponding line on the Cartesian coordinate system.
Plot points, using an x-y table
Graph using intercepts, two separate points(x, 0) and (0, y)
Solve for y, graph using the slope-intercept form. Start on the y-axis, go up/down and then over.
Find an equation for the line that satisfies the given conditions.
Equation of a line: y = mx + b
Point (x, y)
Given two points stack & subtract to find slope m
in y = mx + b, replace x, y, and m - to find b
Find an equation for the line that satisfies the given conditions.
Find the equation of the line containing the two points (-3, 4) and (2, 1)
Find an equation for the line that satisfies the given conditions.
Find the equation of the line containing the two points (-3, 4) and (2, 1)
y – y1 = m(x – x1) y – 1 = -3/5(x – 2) clear the parentheses y – 1 = -3/5x + 6/5 clear the fraction, multiply
by 5 5(y – 1) = -3x + 6 Simplify
5y – 5 = -3x + 6 get all the variables on 1 side
3x + 5y = 11 and the constants on the other side
1 4 3
2 ( 3) 5
Find an equation for the line that satisfies the given conditions.
Parallel lines have the same slope Perpendicular lines have
opposite & reciprocal slope Given an equation: Ax + By = C Solve for y to find m parallel use m perpendicular use - 1/m use the given point (x, y) y = mx + b: replace x, y, and m to find b
Find an equation for the line that satisfies the given conditions.
Perpendicular to 3x – y = 4 and passes through the point (-3,6).