| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.92 |
| Score | 0% | 58% |
What is 2z4 x z7?
| 2z11 | |
| 2z3 | |
| 2z4 | |
| 3z11 |
To multiply terms with exponents, the base of both exponents must be the same. In this case they are so multiply the coefficients and add the exponents:
2z4 x z7
(2 x 1)z(4 + 7)
2z11
What is \( 3 \)\( \sqrt{50} \) - \( 3 \)\( \sqrt{2} \)
| 9\( \sqrt{25} \) | |
| 0\( \sqrt{25} \) | |
| 12\( \sqrt{2} \) | |
| 0\( \sqrt{2} \) |
To subtract these radicals together their radicands must be the same:
3\( \sqrt{50} \) - 3\( \sqrt{2} \)
3\( \sqrt{25 \times 2} \) - 3\( \sqrt{2} \)
3\( \sqrt{5^2 \times 2} \) - 3\( \sqrt{2} \)
(3)(5)\( \sqrt{2} \) - 3\( \sqrt{2} \)
15\( \sqrt{2} \) - 3\( \sqrt{2} \)
Now that the radicands are identical, you can subtract them:
15\( \sqrt{2} \) - 3\( \sqrt{2} \)A machine in a factory has an error rate of 7 parts per 100. The machine normally runs 24 hours a day and produces 10 parts per hour. Yesterday the machine was shut down for 3 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 142.3 | |
| 195.3 | |
| 159.6 | |
| 178.6 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{7}{100} \) x 10 = \( \frac{7 \times 10}{100} \) = \( \frac{70}{100} \) = 0.7 errors per hour
So, in an average hour, the machine will produce 10 - 0.7 = 9.3 error free parts.
The machine ran for 24 - 3 = 21 hours yesterday so you would expect that 21 x 9.3 = 195.3 error free parts were produced yesterday.
A tiger in a zoo has consumed 64 pounds of food in 8 days. If the tiger continues to eat at the same rate, in how many more days will its total food consumtion be 96 pounds?
| 4 | |
| 11 | |
| 9 | |
| 1 |
If the tiger has consumed 64 pounds of food in 8 days that's \( \frac{64}{8} \) = 8 pounds of food per day. The tiger needs to consume 96 - 64 = 32 more pounds of food to reach 96 pounds total. At 8 pounds of food per day that's \( \frac{32}{8} \) = 4 more days.
a(b + c) = ab + ac defines which of the following?
commutative property for multiplication |
|
distributive property for division |
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distributive property for multiplication |
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commutative 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.