I'm pretty sure it is associative, but i haven't studied this in yearsss. <span />
C because there are 10 cents in a dime, and 5 cents in a nickel
Hello there,
Billy-bob went to the store to pick up groceries to pick up some junk food. He started at 8:25 and all day he was shopping at the store. If billy-bob stopped at 1:43, how long was billy-bob there?
Answer:
c = 15/2
Step-by-step explanation:
Multiply both sides of the equation by 9, then reduce the fraction.
9(5/6) = c
15/2 = c
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<em>Alternate methods</em>
You are usually told to "cross-multiply" which means you multiply the expression by the product of the denominators. this would give you ...
9(5) = 6(c)
Then you would divide by the coefficient of c to get ...
(9·5)/6 = c = 15/2
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Since c is multiplied by 1/9, you can solve this by multiplying by the inverse of that coefficient, 9. That is what is done in the first section above. Usually, this does in one step what the "cross-multiply" method does in 2 steps.
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The "cross multiply" step can also be done by multiplying by the least common multiple of the denominators, 18. Then you have ...
18(5/6) = 18(c/9)
15 = 2c
Now, dividing by the coefficient of c gives ...
15/2 = c