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Hi I am trying to do question 8 RAB Consulting in the BPP study text on pg 408. I am having problems with step 6 find the coordinates of A (answer pg 435) Can someone explain why we have to multiply workings 2 with 2.5. Also how did they get to 20a + 685.02 and a = 32.94.
Other than that I have the correct answers but I can’t move forward until I understand these numbers.
Many Thanks
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right now i cannot answer that. but will look at it.
It is a technique for solving simultaneous equations. There are different ways of getting the same answer, but the idea is, if you have two equations with two “unknowns”, if the “unknowns” are the same value, you can subtract one from the other, and effectively cancel them out. Then you are left with only one “unknown”, which is a more straightforward equation.
In the example you refer to, equation one contain 20a. Equation two contains 8a. By multiplying equation two by 2.5, it then also becomes 20a. If you now subtract the first equation from the new one you’ve just created, a is cancelled out, and you are just left with 25.5b=1,456
I forgot to answer your second question.
It appears to be a mistake in the BPP book. As b has been worked out as 57.10, if you multiply that by 12 you should get 685.2 (not 685.02). With a value of b as 685.2 you get the correct answer for a.
20a+685.2=1,344
20a=1,344-685.2
a=32.94
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hey are gonna do Linear Programming tomorrow, Saturday 24th September. we will try to get to that question
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