| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.30 |
| Score | 0% | 66% |
Find the value of a:
-3a + z = 7
-2a - 7z = -8
| -1 | |
| -\(\frac{14}{37}\) | |
| -1\(\frac{18}{23}\) | |
You need to find the value of a so solve the first equation in terms of z:
-3a + z = 7
z = 7 + 3a
then substitute the result (7 - -3a) into the second equation:
-2a - 7(7 + 3a) = -8
-2a + (-7 x 7) + (-7 x 3a) = -8
-2a - 49 - 21a = -8
-2a - 21a = -8 + 49
-23a = 41
a = \( \frac{41}{-23} \)
a = -1\(\frac{18}{23}\)
Which of the following statements about a triangle is not true?
perimeter = sum of side lengths |
|
exterior angle = sum of two adjacent interior angles |
|
area = ½bh |
|
sum of interior angles = 180° |
A triangle is a three-sided polygon. It has three interior angles that add up to 180° (a + b + c = 180°). An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite (d = b + c). The perimeter of a triangle is equal to the sum of the lengths of its three sides, the height of a triangle is equal to the length from the base to the opposite vertex (angle) and the area equals one-half triangle base x height: a = ½ base x height.
If a = 8, b = 5, c = 3, and d = 4, what is the perimeter of this quadrilateral?
| 11 | |
| 26 | |
| 20 | |
| 23 |
Perimeter is equal to the sum of the four sides:
p = a + b + c + d
p = 8 + 5 + 3 + 4
p = 20
If a = c = 2, b = d = 8, and the blue angle = 66°, what is the area of this parallelogram?
| 21 | |
| 24 | |
| 16 | |
| 14 |
The area of a parallelogram is equal to its length x width:
a = l x w
a = a x b
a = 2 x 8
a = 16
What is 9a6 + 3a6?
| 27a6 | |
| 12a6 | |
| 12 | |
| 12a12 |
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.
9a6 + 3a6 = 12a6