| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.18 |
| Score | 0% | 64% |
What is 3a - 5a?
| -2a | |
| 15a2 | |
| -2 | |
| 15a |
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 - 5a = -2a
A right angle measures:
45° |
|
180° |
|
360° |
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90° |
A right angle measures 90 degrees and is the intersection of two perpendicular lines. In diagrams, a right angle is indicated by a small box completing a square with the perpendicular lines.
On this circle, a line segment connecting point A to point D is called:
radius |
|
circumference |
|
diameter |
|
chord |
A circle is a figure in which each point around its perimeter is an equal distance from the center. The radius of a circle is the distance between the center and any point along its perimeter. A chord is a line segment that connects any two points along its perimeter. The diameter of a circle is the length of a chord that passes through the center of the circle and equals twice the circle's radius (2r).
Solve for b:
7b - 5 < -2 - 9b
| b < -1\(\frac{1}{2}\) | |
| b < \(\frac{3}{16}\) | |
| b < 5 | |
| b < 4 |
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.
7b - 5 < -2 - 9b
7b < -2 - 9b + 5
7b + 9b < -2 + 5
16b < 3
b < \( \frac{3}{16} \)
b < \(\frac{3}{16}\)
Solve for a:
a2 - 3a + 9 = 4a - 1
| -1 or -2 | |
| 2 or 5 | |
| 3 or -9 | |
| 1 or -9 |
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 - 3a + 9 = 4a - 1
a2 - 3a + 9 + 1 = 4a
a2 - 3a - 4a + 10 = 0
a2 - 7a + 10 = 0
Next, factor the quadratic equation:
a2 - 7a + 10 = 0
(a - 2)(a - 5) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (a - 2) or (a - 5) must equal zero:
If (a - 2) = 0, a must equal 2
If (a - 5) = 0, a must equal 5
So the solution is that a = 2 or 5