For problems such as this, it can be handy to remember that
.. 1/(1/a +1/b) = ab/(a +b)
The time required to do a job is the inverse of the rate at which the job is done. Rates are added when people work together (in math problems, not in real life).
(2:44)*(3:14)/(2:44 +3:14) = 1:28:52.3
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2:44 = 41/15 hours = 82/30 hours
3:14 = 97/30 hours
Using the formula above, we have a "working together" time of
.. (82/30)*(97/30)/(82/30 +97/30) = 82*97/(30*179) = 3977/2685 . . . hours
.. = 1 hour 28 156/179 minutes
.. = 1 hour 28 minutes 52 52/179 seconds
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Learn to use the fraction functions on your calculator. They can be very helpful.
Answer:
D or answer 4 y=-5/2x+7
Step-by-step explanation:
Well we can first start of by finding the y-intercept.
Note that when x=0, you can find your y-intercept.
Knowing this, and looking at the table, 7 is the y-intercept because when y=7, x=0.
So we can eliminate choices 'a' and 'c,' or answers 1 and 3, because they have the y-intercept as -7, when it's just 7.
Please know that in the equation:
y = mx + b
y = y-coordinate or any given point
mx = slope
b = y-intercept
Now we must find slope
To find the slope we need to do:
(y2 - y1) / (x2 - x1) or rise/run
The two coordinates I choose to use is (0, 7) and (6, -8).
(-8 - 7) / (6 - 0) = -5/2
-5/2 is the slope
Finally, look for an equation that has 7 as the y-intercept and -5/2 as the slope.
Answer: D or answer 4
Answer:
15
19
14
Step-by-step explanation:
Multiplying by 2, the next one would be 160
Answer:
25%
Step-by-step explanation:
20-16=4
So
16…4
1 … 4/16
100…4/16×100
1/4×100
25%
