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if x=7+y and 4x=6-2y, what is the value of x

 May 27, 2017
 #1
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x=7+y, 4x=6-2y = {x=(10/3), y=-((11/3))}

 May 27, 2017
 #2
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{4 x = 6 - 2 y | (equation 1)
x = y + 7 | (equation 2)
Express the system in standard form:
{4 x + 2 y = 6 | (equation 1)
x - y = 7 | (equation 2)
Subtract 1/4 × (equation 1) from equation 2:
{4 x + 2 y = 6 | (equation 1)
0 x - (3 y)/2 = 11/2 | (equation 2)
Divide equation 1 by 2:
{2 x + y = 3 | (equation 1)
0 x - (3 y)/2 = 11/2 | (equation 2)
Multiply equation 2 by 2:
{2 x + y = 3 | (equation 1)
0 x - 3 y = 11 | (equation 2)
Divide equation 2 by -3:
{2 x + y = 3 | (equation 1)
0 x+y = (-11)/3 | (equation 2)
Subtract equation 2 from equation 1:
{2 x+0 y = 20/3 | (equation 1)
0 x+y = -11/3 | (equation 2)
Divide equation 1 by 2:
{x+0 y = 10/3 | (equation 1)
0 x+y = -11/3 | (equation 2)
Collect results:
Answer: | x = 10/3        and        y = -11/3

 May 27, 2017

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