| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.55 |
| Score | 0% | 71% |
Which of the following statements about math operations is incorrect?
you can add monomials that have the same variable and the same exponent |
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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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all of these statements are correct |
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.
Simplify 4a x 7b.
| 28\( \frac{b}{a} \) | |
| 28ab | |
| 28a2b2 | |
| 28\( \frac{a}{b} \) |
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 x 7b = (4 x 7) (a x b) = 28ab
What is 2a - 6a?
| 8a2 | |
| 12a2 | |
| 12a | |
| -4a |
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.
2a - 6a = -4a
If the area of this square is 1, what is the length of one of the diagonals?
| 8\( \sqrt{2} \) | |
| 9\( \sqrt{2} \) | |
| 4\( \sqrt{2} \) | |
| \( \sqrt{2} \) |
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 = \( \sqrt{2} \)
A(n) __________ is to a parallelogram as a square is to a rectangle.
triangle |
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trapezoid |
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quadrilateral |
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rhombus |
A rhombus is a parallelogram with four equal-length sides. A square is a rectangle with four equal-length sides.