| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.86 |
| Score | 0% | 57% |
Solve for z:
-6z + 7 = \( \frac{z}{8} \)
| 1\(\frac{1}{7}\) | |
| \(\frac{16}{17}\) | |
| \(\frac{4}{9}\) | |
| 2\(\frac{6}{11}\) |
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 equal sign and the answer on the other.
-6z + 7 = \( \frac{z}{8} \)
8 x (-6z + 7) = z
(8 x -6z) + (8 x 7) = z
-48z + 56 = z
-48z + 56 - z = 0
-48z - z = -56
-49z = -56
z = \( \frac{-56}{-49} \)
z = 1\(\frac{1}{7}\)
If c = -8 and z = 7, what is the value of -8c(c - z)?
| -60 | |
| 180 | |
| 72 | |
| -960 |
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.)
-8c(c - z)
-8(-8)(-8 - 7)
-8(-8)(-15)
(64)(-15)
-960
What is 3a + 6a?
| -3 | |
| 9a | |
| 9a2 | |
| a2 |
To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.
3a + 6a = 9a
The endpoints of this line segment are at (-2, -8) and (2, 4). What is the slope of this line?
| 1 | |
| -1\(\frac{1}{2}\) | |
| -\(\frac{1}{2}\) | |
| 3 |
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, -8) and (2, 4) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(4.0) - (-8.0)}{(2) - (-2)} \) = \( \frac{12}{4} \)
The endpoints of this line segment are at (-2, 6) and (2, 2). What is the slope-intercept equation for this line?
| y = -3x + 3 | |
| y = -2\(\frac{1}{2}\)x - 1 | |
| y = -x + 3 | |
| 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 4. 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 = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(2.0) - (6.0)}{(2) - (-2)} \) = \( \frac{-4}{4} \)Plugging these values into the slope-intercept equation:
y = -x + 4