| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.32 |
| Score | 0% | 66% |
Solve for a:
-9a - 1 = -8 + 3a
| -2 | |
| -\(\frac{3}{8}\) | |
| \(\frac{7}{12}\) | |
| 3 |
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 equal sign and the answer on the other.
-9a - 1 = -8 + 3a
-9a = -8 + 3a + 1
-9a - 3a = -8 + 1
-12a = -7
a = \( \frac{-7}{-12} \)
a = \(\frac{7}{12}\)
The formula for volume of a cube in terms of height (h), length (l), and width (w) is which of the following?
lw x wh + lh |
|
h x l x w |
|
h2 x l2 x w2 |
|
2lw x 2wh + 2lh |
A cube is a rectangular solid box with a height (h), length (l), and width (w). The volume is h x l x w and the surface area is 2lw x 2wh + 2lh.
A right angle measures:
180° |
|
45° |
|
360° |
|
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.
Solve for a:
a2 + 3a - 37 = 2a + 5
| 4 or -4 | |
| 6 or -7 | |
| 9 or 8 | |
| 7 or 6 |
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 - 37 = 2a + 5
a2 + 3a - 37 - 5 = 2a
a2 + 3a - 2a - 42 = 0
a2 + a - 42 = 0
Next, factor the quadratic equation:
a2 + a - 42 = 0
(a - 6)(a + 7) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (a - 6) or (a + 7) must equal zero:
If (a - 6) = 0, a must equal 6
If (a + 7) = 0, a must equal -7
So the solution is that a = 6 or -7
Which of the following is not true about both rectangles and squares?
all interior angles are right angles |
|
the lengths of all sides are equal |
|
the perimeter is the sum of the lengths of all four sides |
|
the area is length x width |
A rectangle is a parallelogram containing four right angles. Opposite sides (a = c, b = d) are equal and the perimeter is the sum of the lengths of all sides (a + b + c + d) or, comonly, 2 x length x width. The area of a rectangle is length x width. A square is a rectangle with four equal length sides. The perimeter of a square is 4 x length of one side (4s) and the area is the length of one side squared (s2).