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given the equations 9x plus 3/4y =6 and 2x+1/2y=9 by what factor would you multiply the second equation to eliminate y and solve the system through linear combinations

Respuesta :

9x + 3/4y = 6 --------->   9x + 3/4y = 6 
6/4(2x + 1/2y = 9) --->   3x + 3/4y = 13.5 

Add both equations together. The y cancels out.

12x = 19.5

Divide 19.5 by 12 to get: x = 19.5/12 

Plug it in to find y.

9x + 3/4y = 6 
9(19.5/12) + 3/4y = 6
14 5/8 + 3/4y = 6 
-14 5/8             -14 5/8
3/4y = -69/8
------    -------
3/4        3/4
y = -23/2



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