| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.74 |
| Score | 0% | 55% |
Solve for a:
a2 + 7a - 6 = 5a + 2
| -3 or -3 | |
| 2 or -8 | |
| 5 or -6 | |
| 2 or -4 |
The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:
a2 + 7a - 6 = 5a + 2
a2 + 7a - 6 - 2 = 5a
a2 + 7a - 5a - 8 = 0
a2 + 2a - 8 = 0
Next, factor the quadratic equation:
a2 + 2a - 8 = 0
(a - 2)(a + 4) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (a - 2) or (a + 4) must equal zero:
If (a - 2) = 0, a must equal 2
If (a + 4) = 0, a must equal -4
So the solution is that a = 2 or -4
Solve 3a + 5a = -9a - 3x + 2 for a in terms of x.
| -\(\frac{2}{3}\)x + \(\frac{1}{6}\) | |
| 3x + 2 | |
| 1\(\frac{2}{3}\)x - 1\(\frac{1}{3}\) | |
| 1\(\frac{1}{4}\)x - 2\(\frac{1}{4}\) |
To solve this equation, isolate the variable for which you are solving (a) on one side of the equation and put everything else on the other side.
3a + 5x = -9a - 3x + 2
3a = -9a - 3x + 2 - 5x
3a + 9a = -3x + 2 - 5x
12a = -8x + 2
a = \( \frac{-8x + 2}{12} \)
a = \( \frac{-8x}{12} \) + \( \frac{2}{12} \)
a = -\(\frac{2}{3}\)x + \(\frac{1}{6}\)
What is 9a - 7a?
| 2a | |
| 16 | |
| 2a2 | |
| 16a2 |
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.
9a - 7a = 2a
Which of the following is not required to define the slope-intercept equation for a line?
y-intercept |
|
x-intercept |
|
\({\Delta y \over \Delta x}\) |
|
slope |
A line on the coordinate grid can be defined by a slope-intercept equation: y = mx + b. For a given value of x, the value of y can be determined given the slope (m) and y-intercept (b) of the line. The slope of a line is change in y over change in x, \({\Delta y \over \Delta x}\), and the y-intercept is the y-coordinate where the line crosses the vertical y-axis.
If c = -8 and x = -9, what is the value of 4c(c - x)?
| -105 | |
| -60 | |
| 16 | |
| -32 |
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.)
4c(c - x)
4(-8)(-8 + 9)
4(-8)(1)
(-32)(1)
-32