@RRITESH KAKKAR
In the interests of your edification I offer the following illustration of two methods of simultaneous solution...
@RRITESH KAKKAR --- Please read!
I am taking a good deal of time and effort to assist your study of mathematics -- What I require in return is earnest effort and attention to instruction on your part!
Meaning, among other things, that you carefully read this post and make an honest effort at comprehension of the techniques demonstrated herein -- That includes asking questions and practicing the techniques until you are comfortable with them!
We will return to the problem of post #972 following your demonstration of proficiency at simultaneous solution...K?
As an example, we'll use the problem you suggested yesterday -- To wit:
1) Make an algebraic 'statement of the case':
Eq1 ) 4M+6W=1/8 (i.e. 4 men and 6 women working for 1 day complete 1/8 of the job.)
Eq2 ) 3M+7W =1/10 (i.e. 3 men and 7 women working for 1 day complete 1/10 of the job.)
Where:
M = the fraction of the job completed by a single male worker per day.
W = the fraction of the job completed by a single female worker per day.
Clearly, to solve the problem we need only find the value of 'W'
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Simultaneous solution via 'Cancellation':
Note that, for a number of reasons, this is the preferred method of simultaneous solution...
1) Rewrite one of the equations such that a term in an unknown is the additive inverse of the term in the same unknown in the other equation:
Example:
Given Eq1 and Eq2:
4M+6W=1/8
3M+7W =1/10
Rewrite Eq2 thus:
(-4/3)*(3M+7W=1/10) = -4M-(28/3)W=-2/15 --- NOTE: Owing to its linearity, the solution set of the equation is not altered!
2) Add the equations:
4M+6W=1/8
-4M-(28/3)W=-2/15
Resultant equation: 0M-(10/3)W=-1/120
3) Solve the resultant equation for the unknown:
-10/3W=-120 → w=1/400
Thus one woman completes 1/400 of the task per day hence the task completion time for ten women = 40 days...
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Simultaneous solution via 'substitution':
1) Solve either equation for either of the unknowns:
Example:
Given eq1): 4M+6W=1/8
Solve for 'M'
M=(-48W+1)/32
3) Substitute the solution in the other equation
Given eq2): 3M+7W=1/10
Substitute 'M' in with "((-48W+1)/32)
Resulting equation: 3*((-48W+1)/32)+7W=1/10
4) Solve the resulting equation for the unknown:
3*((-48W+1)/32)+7W=1/10→W=1/400
Again the solution --- One woman completes 1/400 of the task per day hence task completion time for ten women = 40 days...
Note that the techniques illustrated above may be applied to any number of linear equations containing any number of unknowns --- and, with certain qualifications, to non-linear equations...
I expect you to have questions! -- Please ask them!!!!
Best regards
HP
PS --- Note that the productivity ratio of the men to the women is 11:1 --- Aye, aye! aye! --- More slackers for @Aleph(0) to dismiss!![]()
Yes i have understand the method.
well explained .