SOLUTION: If the system 4x-5y=4 amd 8x-5y=-5 is to be solved using the addition by what constant should one of the equations be multipled if the x terms are to drop out? a) 1/2 b) 4 c)

Question 179433: If the system 4x-5y=4 amd 8x-5y=-5 is to be solved using the addition by what constant should one of the equations be multipled if the x terms are to drop out?
a) 1/2
b) 4
c) -2
d) -4
explain your answer
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
Notice how the x coefficients are 4 and 8. So the LCM is 8 (since they both go into 8). The goal is to make the coefficients equal but opposite. So this means that we want -8 and 8 (so they add to 0). This means that you multiply 4 by -2 to get -8.

So the answer is C) -2
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