| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.47 |
| Score | 0% | 69% |
Simplify (5a)(9ab) + (9a2)(7b).
| -18ab2 | |
| 18a2b | |
| 108a2b | |
| 224ab2 |
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.
(5a)(9ab) + (9a2)(7b)
(5 x 9)(a x a x b) + (9 x 7)(a2 x b)
(45)(a1+1 x b) + (63)(a2b)
45a2b + 63a2b
108a2b
If side x = 13cm, side y = 12cm, and side z = 13cm what is the perimeter of this triangle?
| 28cm | |
| 27cm | |
| 31cm | |
| 38cm |
The perimeter of a triangle is the sum of the lengths of its sides:
p = x + y + z
p = 13cm + 12cm + 13cm = 38cm
If a = c = 8, b = d = 7, what is the area of this rectangle?
| 3 | |
| 56 | |
| 9 | |
| 45 |
The area of a rectangle is equal to its length x width:
a = l x w
a = a x b
a = 8 x 7
a = 56
For this diagram, the Pythagorean theorem states that b2 = ?
c2 + a2 |
|
c2 - a2 |
|
a2 - c2 |
|
c - a |
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, \(c = \sqrt{a + b}\)
Which of the following statements about math operations is incorrect?
you can subtract monomials that have the same variable and the same exponent |
|
you can add monomials that have the same variable and the same exponent |
|
you can multiply monomials that have different variables and different exponents |
|
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.