| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.50 |
| Score | 0% | 70% |
A(n) __________ is two expressions separated by an equal sign.
problem |
|
equation |
|
expression |
|
formula |
An equation is two expressions separated by an equal sign. The key to solving equations is to 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.
If a = c = 9, b = d = 7, and the blue angle = 70°, what is the area of this parallelogram?
| 35 | |
| 9 | |
| 63 | |
| 6 |
The area of a parallelogram is equal to its length x width:
a = l x w
a = a x b
a = 9 x 7
a = 63
A coordinate grid is composed of which of the following?
y-axis |
|
x-axis |
|
origin |
|
all of these |
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 angle a = 42° and angle b = 61° what is the length of angle d?
| 138° | |
| 159° | |
| 133° | |
| 113° |
An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite:
d° = b° + c°
To find angle c, remember that the sum of the interior angles of a triangle is 180°:
180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 42° - 61° = 77°
So, d° = 61° + 77° = 138°
A shortcut to get this answer is to remember that angles around a line add up to 180°:
a° + d° = 180°
d° = 180° - a°
d° = 180° - 42° = 138°
Solve for a:
a2 - a - 20 = 0
| 4 or -6 | |
| -4 or 5 | |
| 6 or -7 | |
| 6 or -9 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
a2 - a - 20 = 0
(a + 4)(a - 5) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (a + 4) or (a - 5) must equal zero:
If (a + 4) = 0, a must equal -4
If (a - 5) = 0, a must equal 5
So the solution is that a = -4 or 5