| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.65 |
| Score | 0% | 53% |
Simplify (4a)(2ab) - (2a2)(8b).
| 24ab2 | |
| 60a2b | |
| 8ab2 | |
| -8a2b |
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.
(4a)(2ab) - (2a2)(8b)
(4 x 2)(a x a x b) - (2 x 8)(a2 x b)
(8)(a1+1 x b) - (16)(a2b)
8a2b - 16a2b
-8a2b
Solve for y:
y2 + 3y - 27 = 5y - 3
| 9 or 7 | |
| 1 or -7 | |
| -4 or 6 | |
| 8 or -9 |
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:
y2 + 3y - 27 = 5y - 3
y2 + 3y - 27 + 3 = 5y
y2 + 3y - 5y - 24 = 0
y2 - 2y - 24 = 0
Next, factor the quadratic equation:
y2 - 2y - 24 = 0
(y + 4)(y - 6) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (y + 4) or (y - 6) must equal zero:
If (y + 4) = 0, y must equal -4
If (y - 6) = 0, y must equal 6
So the solution is that y = -4 or 6
The dimensions of this trapezoid are a = 5, b = 2, c = 8, d = 5, and h = 3. What is the area?
| 7\(\frac{1}{2}\) | |
| 10\(\frac{1}{2}\) | |
| 37\(\frac{1}{2}\) | |
| 40 |
The area of a trapezoid is one-half the sum of the lengths of the parallel sides multiplied by the height:
a = ½(b + d)(h)
a = ½(2 + 5)(3)
a = ½(7)(3)
a = ½(21) = \( \frac{21}{2} \)
a = 10\(\frac{1}{2}\)
Which of the following is not true about both rectangles and squares?
the perimeter is the sum of the lengths of all four sides |
|
the lengths of all sides are equal |
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all interior angles are right angles |
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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).
The endpoints of this line segment are at (-2, 10) and (2, -2). What is the slope-intercept equation for this line?
| y = x - 3 | |
| y = -3x + 4 | |
| y = 1\(\frac{1}{2}\)x + 2 | |
| y = 2x + 1 |
The slope-intercept equation for a line is y = mx + b where m is the slope and b is the y-intercept of the line. From the graph, you can see that the y-intercept (the y-value from the point where the line crosses the y-axis) is 4. The slope of this line is the change in y divided by the change in x. The endpoints of this line segment are at (-2, 10) and (2, -2) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(-2.0) - (10.0)}{(2) - (-2)} \) = \( \frac{-12}{4} \)Plugging these values into the slope-intercept equation:
y = -3x + 4