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5 votes
4x+7y=-
20
2x-5 y=-10

User ShujatAli
by
8.2k points

1 Answer

2 votes

Answer:

x = -5 , y = 0

Explanation:

Solve the following system:

{4 x + 7 y = -20 | (equation 1)

2 x - 5 y = -10 | (equation 2)

Subtract 1/2 × (equation 1) from equation 2:

{4 x + 7 y = -20 | (equation 1)

0 x - (17 y)/2 = 0 | (equation 2)

Multiply equation 2 by 2/17:

{4 x + 7 y = -20 | (equation 1)

0 x - y = 0 | (equation 2)

Multiply equation 2 by -1:

{4 x + 7 y = -20 | (equation 1)

0 x+y = 0 | (equation 2)

Subtract 7 × (equation 2) from equation 1:

{4 x+0 y = -20 | (equation 1)

0 x+y = 0 | (equation 2)

Divide equation 1 by 4:

{x+0 y = -5 | (equation 1)

0 x+y = 0 | (equation 2)

Collect results:

Answer: {x = -5 , y = 0

User Jturnbull
by
8.0k points