Three runners, Dirk, Edith, and Foley all start at the same time for a $24$ km race, and each of them runs at a constant speed.
1 answer:
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Complete Question:
Jamie used the distributive property to find the product of s(t) and h(t). His work was marked incorrect. Identify Jamie's mistake. What advice would you give Jamie to avoid this mistake in the future?
s(t)•h(t)= (3x-4)(2x-8)
= 6x² - 24x -8x - 32
= 6x² - 32x - 32
Answer:
Jamie made a mistake in his second line (6x² - 24x -8x - 32), by wrongly multiplying the operation signs. The last term should be +32, not -32.
Advice: Jamie should take note of the rule that applies when multiplying signs.
Step-by-step Explanation::
To find out where exactly Jamie made mistake, let's find the product of the given functions, step by step:
s(t)•h(t)= (3x-4)(2x-8)
Using distributive property, do the following:
(this is where Jamie made mistake. -4 * -8 = +32. NOT -32.)
Add like terms
Jamie made a mistake in multiplying negative × negative. The last term in "6x² - 24x -8x - 32", should be +32. Negative × negative = +.
Therefore, it is advisable for Jamie to always take note of the rule that applies when multiplying signs.
Answer: The correct option is (C) Packages x 3 = Pens
Step-by-step explanation: Given that each package of pens contains 3 pens.
We are to choose the correct mathematical relation between number of pens and number of packages.
Let, n represents the number of pens and N represents the number of packages.
Then, according to the given information, we have
Thus, the correct relation is
Packages x 3 = Pens.
Option (C) is CORRECT.