| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.44 |
| Score | 0% | 49% |
Simplify (2a)(6ab) - (6a2)(9b).
| 42ab2 | |
| 120a2b | |
| 120ab2 | |
| -42a2b |
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.
(2a)(6ab) - (6a2)(9b)
(2 x 6)(a x a x b) - (6 x 9)(a2 x b)
(12)(a1+1 x b) - (54)(a2b)
12a2b - 54a2b
-42a2b
Find the value of b:
-5b + y = -1
3b + 5y = -6
| -\(\frac{34}{39}\) | |
| -\(\frac{9}{11}\) | |
| -\(\frac{15}{32}\) | |
| -\(\frac{1}{28}\) |
You need to find the value of b so solve the first equation in terms of y:
-5b + y = -1
y = -1 + 5b
then substitute the result (-1 - -5b) into the second equation:
3b + 5(-1 + 5b) = -6
3b + (5 x -1) + (5 x 5b) = -6
3b - 5 + 25b = -6
3b + 25b = -6 + 5
28b = -1
b = \( \frac{-1}{28} \)
b = -\(\frac{1}{28}\)
Which of the following statements about parallel lines with a transversal is not correct?
same-side interior angles are complementary and equal each other |
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all of the angles formed by a transversal are called interior angles |
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all acute angles equal each other |
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angles in the same position on different parallel lines are called corresponding angles |
Parallel lines are lines that share the same slope (steepness) and therefore never intersect. A transversal occurs when a set of parallel lines are crossed by another line. All of the angles formed by a transversal are called interior angles and angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°) and are called corresponding angles. Alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°) and all acute angles (a° = c° = w° = z°) and all obtuse angles (b° = d° = x° = y°) equal each other. Same-side interior angles are supplementary and add up to 180° (e.g. a° + d° = 180°, d° + c° = 180°).
A cylinder with a radius (r) and a height (h) has a surface area of:
2(π r2) + 2π rh |
|
π r2h2 |
|
π r2h |
|
4π r2 |
A cylinder is a solid figure with straight parallel sides and a circular or oval cross section with a radius (r) and a height (h). The volume of a cylinder is π r2h and the surface area is 2(π r2) + 2π rh.
Solve for c:
c2 - 2c - 28 = -c + 2
| 4 or -4 | |
| -5 or 6 | |
| 9 or 3 | |
| -2 or -8 |
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:
c2 - 2c - 28 = -c + 2
c2 - 2c - 28 - 2 = -c
c2 - 2c + c - 30 = 0
c2 - c - 30 = 0
Next, factor the quadratic equation:
c2 - c - 30 = 0
(c + 5)(c - 6) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (c + 5) or (c - 6) must equal zero:
If (c + 5) = 0, c must equal -5
If (c - 6) = 0, c must equal 6
So the solution is that c = -5 or 6