| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.97 |
| Score | 0% | 59% |
Which of the following is not required to define the slope-intercept equation for a line?
\({\Delta y \over \Delta x}\) |
|
y-intercept |
|
x-intercept |
|
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 angle a = 37° and angle b = 62° what is the length of angle d?
| 114° | |
| 143° | |
| 154° | |
| 159° |
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° - 37° - 62° = 81°
So, d° = 62° + 81° = 143°
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° - 37° = 143°
Simplify 6a x 9b.
| 15ab | |
| 54\( \frac{a}{b} \) | |
| 54\( \frac{b}{a} \) | |
| 54ab |
To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.
6a x 9b = (6 x 9) (a x b) = 54ab
Solve for b:
4b + 6 > \( \frac{b}{2} \)
| b > -2\(\frac{2}{7}\) | |
| b > -\(\frac{30}{53}\) | |
| b > -1\(\frac{5}{7}\) | |
| b > 2\(\frac{2}{13}\) |
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.
4b + 6 > \( \frac{b}{2} \)
2 x (4b + 6) > b
(2 x 4b) + (2 x 6) > b
8b + 12 > b
8b + 12 - b > 0
8b - b > -12
7b > -12
b > \( \frac{-12}{7} \)
b > -1\(\frac{5}{7}\)
If the area of this square is 1, what is the length of one of the diagonals?
| 3\( \sqrt{2} \) | |
| 2\( \sqrt{2} \) | |
| \( \sqrt{2} \) | |
| 5\( \sqrt{2} \) |
To find the diagonal we need to know the length of one of the square's sides. We know the area and the area of a square is the length of one side squared:
a = s2
so the length of one side of the square is:
s = \( \sqrt{a} \) = \( \sqrt{1} \) = 1
The Pythagorean theorem defines the square of the hypotenuse (diagonal) of a triangle with a right angle as the sum of the squares of the other two sides:
c2 = a2 + b2
c2 = 12 + 12
c2 = 2
c = \( \sqrt{2} \)