| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.26 |
| Score | 0% | 65% |
Solve for z:
5z - 7 > \( \frac{z}{3} \)
| z > 2\(\frac{4}{5}\) | |
| z > \(\frac{1}{2}\) | |
| z > 1\(\frac{1}{7}\) | |
| z > 1\(\frac{1}{2}\) |
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.
5z - 7 > \( \frac{z}{3} \)
3 x (5z - 7) > z
(3 x 5z) + (3 x -7) > z
15z - 21 > z
15z - 21 - z > 0
15z - z > 21
14z > 21
z > \( \frac{21}{14} \)
z > 1\(\frac{1}{2}\)
What is 8a + 8a?
| 64a | |
| 16 | |
| a2 | |
| 16a |
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.
8a + 8a = 16a
Factor y2 - 6y - 27
| (y + 9)(y - 3) | |
| (y - 9)(y + 3) | |
| (y - 9)(y - 3) | |
| (y + 9)(y + 3) |
To factor a quadratic expression, apply the FOIL method (First, Outside, Inside, Last) in reverse. First, find the two Last terms that will multiply to produce -27 as well and sum (Inside, Outside) to equal -6. For this problem, those two numbers are -9 and 3. Then, plug these into a set of binomials using the square root of the First variable (y2):
y2 - 6y - 27
y2 + (-9 + 3)y + (-9 x 3)
(y - 9)(y + 3)
If a = c = 9, b = d = 5, what is the area of this rectangle?
| 16 | |
| 45 | |
| 6 | |
| 30 |
The area of a rectangle is equal to its length x width:
a = l x w
a = a x b
a = 9 x 5
a = 45
If the area of this square is 1, what is the length of one of the diagonals?
| 7\( \sqrt{2} \) | |
| \( \sqrt{2} \) | |
| 5\( \sqrt{2} \) | |
| 2\( \sqrt{2} \) |
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 = \( \sqrt{2} \)