SOLUTION: addition method 4x-2y=5 24x-9y=-3 by what constant should one of the eauations be multiplied if the x terms are to drop out?

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Question 166664: addition method
4x-2y=5
24x-9y=-3
by what constant should one of the eauations be multiplied if the x terms are to drop out?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Notice how the x coefficients are 4 and 24. Also, notice how the LCM of 4 and 24 is 24. This means that we must multiply 4 by 6 to get to the LCM 24. Now the goal is to make the x coefficients equal but have an opposite sign.


So if we multiply the first equation by -6 (to make the first coefficient negative), we'll get -24x%2B12y=-30 which when added to 24x-9y=-3 we'll get -24x%2B24x%2B12y-9y=-30-3 which becomes 3y=-33.