| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.23 |
| Score | 0% | 65% |
A coordinate grid is composed of which of the following?
x-axis |
|
origin |
|
all of these |
|
y-axis |
The coordinate grid is composed of a horizontal x-axis and a vertical y-axis. The center of the grid, where the x-axis and y-axis meet, is called the origin.
If b = 5 and y = -9, what is the value of -2b(b - y)?
| -405 | |
| -140 | |
| 432 | |
| -126 |
To solve this equation, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)
-2b(b - y)
-2(5)(5 + 9)
-2(5)(14)
(-10)(14)
-140
The endpoints of this line segment are at (-2, -6) and (2, 2). What is the slope-intercept equation for this line?
| y = -2\(\frac{1}{2}\)x - 2 | |
| y = -2\(\frac{1}{2}\)x + 0 | |
| y = 2x - 2 | |
| y = x + 4 |
The slope-intercept equation for a line is y = mx + b where m is the slope and b is the y-intercept of the line. From the graph, you can see that the y-intercept (the y-value from the point where the line crosses the y-axis) is -2. The slope of this line is the change in y divided by the change in x. The endpoints of this line segment are at (-2, -6) and (2, 2) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(2.0) - (-6.0)}{(2) - (-2)} \) = \( \frac{8}{4} \)Plugging these values into the slope-intercept equation:
y = 2x - 2
If the area of this square is 1, what is the length of one of the diagonals?
| 8\( \sqrt{2} \) | |
| 7\( \sqrt{2} \) | |
| \( \sqrt{2} \) | |
| 9\( \sqrt{2} \) |
To find the diagonal we need to know the length of one of the square's sides. We know the area and the area of a square is the length of one side squared:
a = s2
so the length of one side of the square is:
s = \( \sqrt{a} \) = \( \sqrt{1} \) = 1
The Pythagorean theorem defines the square of the hypotenuse (diagonal) of a triangle with a right angle as the sum of the squares of the other two sides:
c2 = a2 + b2
c2 = 12 + 12
c2 = 2
c = \( \sqrt{2} \)
Solve for b:
6b - 3 > -4 + 4b
| b > -\(\frac{1}{2}\) | |
| b > \(\frac{5}{7}\) | |
| b > -1\(\frac{1}{2}\) | |
| b > -1\(\frac{2}{7}\) |
To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the > sign and the answer on the other.
6b - 3 > -4 + 4b
6b > -4 + 4b + 3
6b - 4b > -4 + 3
2b > -1
b > \( \frac{-1}{2} \)
b > -\(\frac{1}{2}\)