http://www.mathopenref.com/coordintro.html
http://www.cpalms.org/Public/PreviewResourceAssessment/Preview/70464
Explanation:
Addition of fractions can be accomplished using the formula ...
a/b + c/d = (ad +bc)/(bd)
Usually, you are asked to find the common denominator and rewrite the fractions using that denominator. It is not necessary, but it can save a step in the reduction of the final result. Here, we'll use the formula, then reduce the result to lowest terms.
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13. 5/6 +9/11 = (5·11 +6·9)/(6·11) = 109/66 = 1 43/66
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14. 7/20 -5/8 = (7·8 -20·5)/(20·8) = -44/160 = -11/40
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15. 1/5 -1/12 = (1·12 -5·1)/(5·12) = 7/60
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Dividing fractions can be accomplished different ways. I was taught to multiply by the inverse of the divisor. ("Invert and multiply.") Here, that means the problem (2/7) / (1/13) can be rewritten as ...
(2/7) × (13/1) . . . . . where 13/1 is the inverse of 1/13.
You can also express the fractions over a common denominator. In that case, the quotient is the ratio of the numerators. Perhaps a little less obvious is that you can express the fractions using a common numerator. Then the quotient is the inverse of the ratio of the denominators: (2/7) / (2/26) = 26/7. (You can see how this works if you "invert and multiply" the fractions with common numerators. Those numerators cancel.)
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16. (2/7)/(1/13) = 2/7·13/1 = 26/7 = 3 5/7
Answer:
Ralph's current age is 18.
Step-by-step explanation:
Let r and s represent the current ages of Ralph and Sara respectively. Our task here is to determine r, Ralph's age now.
If Ralph is 3 times as old as Sara now, then r = 3s.
Six years from now, Ralph's age will be r + 6 and Sara's will be s + 6. Ralph will be only twice as old as Sara will be then. This can be represented algebraically as
r + 6 = 2(s + 6).
We now have the following system of linear equations to solve:
r + 6 = 2s + 12, or r - 2s = 6, and r = 3s (found earlier, see above).
r - 2s = 6
r = 3s
Substituting 3s for r in r - 2s = 6, we get 3s = 2s + 6, or s = 6. Sara is 6 years old now, meaning that Ralph is 3(6 years), or 18 years old.
Ralph's current age is 18.
Answer:
64.69e221
Step-by-step explanation:
When choosing, the combination formula for selection is used. That is when selecting "r" number of items from a possible "n" items, then the number of ways is denoted as:
nCr = n! / (n-r)! × r!
Since 66 string quartet have to be chosen and the 3 genres must be equally represented in the string quartet, then we must have 22 number of each genre in it.
Number of ways to select 22 mendelssohn from possible 66 = 66C22 = 1.82 × 10^17
Number of ways to select 22 Beethoven from possible 1616 = 1616C22 = 2.97 × 10^49
Number of ways to select 22 Haydn from possible 6868 = 6868C22 = 2.2 × 10^63
Total number of ways to arrange these 66 schedules = 66! = 5.44 × 10^92
Number of possible schedule = [1.82 * 10^17] * [2.97*10^49] * [2.2*10^63] * [5.44*10^92]
=64.69 ×10^221. ≈64.69e221
Answer:
A.) 6.4 units
Step-by-step explanation:
We can use the Pythagorean theorem to find the length of AB.
If we find the horizontal and vertical distance of A and B, we form a triangle, with leg lengths of 5 and 4.
Now, we just solve using the Pythagorean theorem.
5^2 = 25
4^2 = 16
25 + 16 = 41
sqrt 41 ≈ 6.4 units.
Hope this helps!
If there is something wrong, just let me know.