Answer:
x = 7
, y = -1
Step-by-step explanation by elimination:
Solve the following system:
{10 x + 10 y = 60 | (equation 1)
5 x - 5 y = 40 | (equation 2)
Subtract 1/2 × (equation 1) from equation 2:
{10 x + 10 y = 60 | (equation 1)
0 x - 10 y = 10 | (equation 2)
Divide equation 1 by 10:
{x + y = 6 | (equation 1)
0 x - 10 y = 10 | (equation 2)
Divide equation 2 by 10:
{x + y = 6 | (equation 1)
0 x - y = 1 | (equation 2)
Multiply equation 2 by -1:
{x + y = 6 | (equation 1)
0 x+y = -1 | (equation 2)
Subtract equation 2 from equation 1:
{x+0 y = 7 | (equation 1)
0 x+y = -1 | (equation 2)
Collect results:
Answer: {x = 7
, y = -1
