Answer:
x = 1 , y = 3 thus D: is your answer
Explanation:
Solve the following system:
{y - 2 x = 1 | (equation 1)
y - 4 x = -1 | (equation 2)
Swap equation 1 with equation 2:
{-(4 x) + y = -1 | (equation 1)
-(2 x) + y = 1 | (equation 2)
Subtract 1/2 × (equation 1) from equation 2:
{-(4 x) + y = -1 | (equation 1)
0 x+y/2 = 3/2 | (equation 2)
Multiply equation 2 by 2:
{-(4 x) + y = -1 | (equation 1)
0 x+y = 3 | (equation 2)
Subtract equation 2 from equation 1:
{-(4 x)+0 y = -4 | (equation 1)
0 x+y = 3 | (equation 2)
Divide equation 1 by -4:
{x+0 y = 1 | (equation 1)
0 x+y = 3 | (equation 2)
Collect results:
Answer: {x = 1 , y = 3