2. Equations and Inequalities Flashcards
In the rectangular coordinate system, the horizontal number line is called the ______.
x-axis
In the rectangular coordinate system, the vertical number line is called the ______.
y-axis
In the rectangular coordinate system, the point of intersection of the horizontal axis and the vertical axis is called the ______.
origin
The axes of the rectangular coordinate system divide
the plane into regions, called ______. There are ______ of these regions.
quadrants
four
The first number in an ordered pair such as (8, 3) is called the ______. The second number in such an ordered pair is called the _______.
x-coordinate
y-coordinate
The ordered pair (4, 19) is a/an ______ of the
equation y = x² + 3 because when 4 is substituted
for x and 19 is substituted for y, we obtain a true statement. We also say that (4, 19) ______ the
equation.
solution
satisfies
The x-coordinate of a point where a graph crosses the
x-axis is called a/an ______. The y-coordinate of such
a point is always ______.
x-intercept
zero
The y-coordinate of a point where a graph crosses the
y-axis is called a/an ______. The x-coordinate of such
a point is always ______.
y-intercept
zero
An equation in the form ax + b = 0, a ≠ 0, such as 3x + 17 = 0, is called a/an ______ equation in one variable.
linear
Two or more equations that have the same solution set are called ______ equations.
equivalent
The first step in solving the 7x + 3(x - 2) = 2 x + 10 is to ______.
apply the distributive property
The fractions in the equation x/4 = 2 + (x - 3)/3 can be eliminated by multiplying both sides by the ______ of x/4 and (x-3)/3, which is ______.
least common denominator
12
We reject any proposed solution of a rational equation that causes a denominator to equal ______.
0
The first step in solving 4/x + 1/2 = 5/x is to multiply both sides by _______.
2x
An equation that is true for all real numbers for which both sides are defined is called a/an _______.
identity
An equation that is not true for even one real number is called a/an _______ equation.
inconsistent
According to the U.S. Office of Management and Budget, the 2011 budget for defense exceeded the budget for education by $658.6 billion. If x represents the budget for education, in billions of dollars, the budget for defense can be represented by ______.
x + 658.6
In 2000, 31% of U.S. adults viewed a college education as essential for success. For the period from 2000 through 2010, this percentage increased by approximately 2.4 each year. The percentage of U.S. adults who viewed a college education as essential for
success x years after 2000 can be represented by _______.
31 + 2.4x
A text message plan costs $4 per month plus $0.15
per text. The monthly cost for x text messages can be
represented by ______.
4 + 0.15x
purchased a computer after a 15% price reduction. If
x represents the computer’s original price, the reduced
price can be represented by ______.
x - 0.15x
or
0.85x
The combined yearly interest for x dollars invested
at 12% and 30,000 – x dollars invested at 9% is _______.
0.12x + 0.09(30,000 - x)
Solving a formula for a variable means rewriting the
formula so that the variable is ______.
isolated on one side
The first step in solving IR + Ir = E for I is to obtain
a single occurrence of I by ______ I from the two terms on the left.
factoring
The imaginary unit i is defined as i = _______, where
i² = _______.
√–1
–1
The set of all numbers in the form a + bi is called the
set of ______ numbers. If b ≠ 0, then the number is
also called a/an ______ number. If b = 0, then the
number is also called a/an ______ number.
complex
imaginary
real
–9i + 3i = ______.
–6i
10i – (–4i) = _______
14i
Consider the following multiplication problem:
(3 + 2i)(6 – 5i)
Using the FOIL method, the product of the first terms is _______, the product of the outside terms is _______. The product of the last terms in terms of i² is _______, which simplifies to _______.
18
–15i
12i
–10i²
10
The conjugate of 2 – 9i is ______.
2 + 9i
The division (7 + 4i) / (2 – 5i) is performed by multiplying the numerator and denominator by _______.
2 + 5i