SOLUTION: Hello. Im having some problem doing my homework and I need some help. I have 4 questions. 1. 1/7+7/9-1/6 2. V=1/3Bh for B A. B=h/3V B.B=3h/V C. B=V/3h D. B=

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: Hello. Im having some problem doing my homework and I need some help. I have 4 questions. 1. 1/7+7/9-1/6 2. V=1/3Bh for B A. B=h/3V B.B=3h/V C. B=V/3h D. B=      Log On


   

Question 74542: Hello. Im having some problem doing my homework and I need some help.
I have 4 questions.
1. 1/7+7/9-1/6
2. V=1/3Bh for B
A. B=h/3V B.B=3h/V C. B=V/3h D. B=3V/h
3.The formula used to convert a temperature given in degrees fahrenheit to degrees celsius is C=5/9(F-32). What is the fahrenheit temperature when th celsius temperature is -5?
4. A bike road race starts at an elevation of 780ft and passes through 5 stages where the elevation changes by 486 ft, -641 ft, 96 ft, and 494 ft. At what elevation does the race end?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
1.
When adding fractions we need to make sure they all have the same denominator. To find the common denominator, we need to find the LCM. The LCM is the product of the denominators divided by the GCF. So 7*9=63 and since the GCF is 1 we get 63. The LCM between 63 and 6 is
%2863%2A6%29%2F3=126
So the LCM is 126 which is our common denominator.
1%2F7%2B7%2F9-1%2F6
%2818%2F18%29%281%2F7%29%2B%2814%2F14%29%287%2F9%29-%2821%2F21%29%281%2F6%29Multiply each term by a form of 1 to get the common denominator.
18%2F126%2B98%2F126-21%2F126
%2818%2B98-21%29%2F126
95%2F126


2.
To solve for b, divide both sides by (1/3h)
V=%281%2F3%29Bh
V%2F%28%281%2F3%29h%29=%28cross%281%2F3%29B%2Across%28h%29%29%2Fcross%28%281%2F3%29h%29
B=3V%2Fh
So the answer is D.


3.
To find F, plug in c=-5.
-5=%285%2F9%29%28F-32%29
-5%289%2F5%29=cross%289%2F5%29%28cross%285%2F9%29%28F-32%29%29Multiply both sides by 9/5
-cross%285%29%289%2Fcross%285%29%29=F-32
-9%2B32=F%2Bcross%28-32%2B32%29Now add 32 to both sides
23=F
So the temperature in Fahrenheit is 23 degrees


4.
If the elevation changes by 486 feet then that means we add 486 feet to the current elevation. So if we're at 780 feet and we add 486 feet we get 1,266 feet. If our elevation changes by -641 feet, we subtract 641 from our current elevation of 1266. So we get
1266-641=625
Continue this until all the elevation changes are accounted for.
625%2B96%2B494=1215
So the final elevation is 1,215 feet.