| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.03 |
| Score | 0% | 61% |
Which of the following statements about math operations is incorrect?
all of these statements are correct |
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you can multiply monomials that have different variables and different exponents |
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you can subtract monomials that have the same variable and the same exponent |
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you can add monomials that have the same variable and the same exponent |
You can only add or subtract monomials that have the same variable and the same exponent. For example, 2a + 4a = 6a and 4a2 - a2 = 3a2 but 2a + 4b and 7a - 3b cannot be combined. However, you can multiply and divide monomials with unlike terms. For example, 2a x 6b = 12ab.
The formula for the area of a circle is which of the following?
a = π d2 |
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a = π r |
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a = π r2 |
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a = π d |
The circumference of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The area of a circle is π x (radius)2 : a = π r2.
For this diagram, the Pythagorean theorem states that b2 = ?
c2 + a2 |
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a2 - c2 |
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c - a |
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c2 - a2 |
The Pythagorean theorem defines the relationship between the side lengths of a right triangle. The length of the hypotenuse squared (c2) is equal to the sum of the two perpendicular sides squared (a2 + b2): c2 = a2 + b2 or, solved for c, \(c = \sqrt{a + b}\)
What is 3a7 - 4a7?
| -1a7 | |
| a714 | |
| -1 | |
| 7a14 |
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.
3a7 - 4a7 = -1a7
Solve -7c - 7c = 4c - 4x - 5 for c in terms of x.
| -\(\frac{8}{11}\)x + \(\frac{8}{11}\) | |
| -\(\frac{1}{6}\)x - \(\frac{2}{3}\) | |
| -\(\frac{3}{11}\)x + \(\frac{5}{11}\) | |
| -13x + 9 |
To solve this equation, isolate the variable for which you are solving (c) on one side of the equation and put everything else on the other side.
-7c - 7x = 4c - 4x - 5
-7c = 4c - 4x - 5 + 7x
-7c - 4c = -4x - 5 + 7x
-11c = 3x - 5
c = \( \frac{3x - 5}{-11} \)
c = \( \frac{3x}{-11} \) + \( \frac{-5}{-11} \)
c = -\(\frac{3}{11}\)x + \(\frac{5}{11}\)