| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.05 |
| Score | 0% | 61% |
| 5.6 | |
| 1 | |
| 7.2 | |
| 2.0 |
1
a(b + c) = ab + ac defines which of the following?
commutative property for division |
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commutative property for multiplication |
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distributive property for multiplication |
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distributive property for division |
The distributive property for multiplication helps in solving expressions like a(b + c). It specifies that the result of multiplying one number by the sum or difference of two numbers can be obtained by multiplying each number individually and then totaling the results: a(b + c) = ab + ac. For example, 4(10-5) = (4 x 10) - (4 x 5) = 40 - 20 = 20.
What is 8z4 + z4?
| 9z16 | |
| 7z4 | |
| 9z8 | |
| 9z4 |
To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so add the coefficients and retain the base and exponent:
8z4 + 1z4
(8 + 1)z4
9z4
A circular logo is enlarged to fit the lid of a jar. The new diameter is 60% larger than the original. By what percentage has the area of the logo increased?
| 30% | |
| 20% | |
| 37\(\frac{1}{2}\)% | |
| 32\(\frac{1}{2}\)% |
The area of a circle is given by the formula A = πr2 where r is the radius of the circle. The radius of a circle is its diameter divided by two so A = π(\( \frac{d}{2} \))2. If the diameter of the logo increases by 60% the radius (and, consequently, the total area) increases by \( \frac{60\text{%}}{2} \) = 30%
What is \( \frac{3}{5} \) - \( \frac{9}{7} \)?
| 2 \( \frac{2}{8} \) | |
| -\(\frac{24}{35}\) | |
| 2 \( \frac{4}{35} \) | |
| 2 \( \frac{3}{10} \) |
To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 5 are [5, 10, 15, 20, 25, 30, 35, 40, 45, 50] and the first few multiples of 7 are [7, 14, 21, 28, 35, 42, 49, 56, 63, 70]. The first few multiples they share are [35, 70] making 35 the smallest multiple 5 and 7 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{3 x 7}{5 x 7} \) - \( \frac{9 x 5}{7 x 5} \)
\( \frac{21}{35} \) - \( \frac{45}{35} \)
Now, because the fractions share a common denominator, you can subtract them:
\( \frac{21 - 45}{35} \) = \( \frac{-24}{35} \) = -\(\frac{24}{35}\)