Question

Solve by elimination -5x+8y=-27 -8x+7y=-20

Answer 1

Answer:

x = -1 , y = -4

Step-by-step explanation by elimination:

Solve the following system:

{8 y - 5 x = -27 | (equation 1)

7 y - 8 x = -20 | (equation 2)

Swap equation 1 with equation 2:

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

-(5 x) + 8 y = -27 | (equation 2)

Subtract 5/8 × (equation 1) from equation 2:

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

0 x+(29 y)/8 = (-29)/2 | (equation 2)

Multiply equation 2 by 8/29:

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

0 x+y = -4 | (equation 2)

Subtract 7 × (equation 2) from equation 1:

{-(8 x)+0 y = 8 | (equation 1)

0 x+y = -4 | (equation 2)

Divide equation 1 by -8:

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

0 x+y = -4 | (equation 2)

Collect results:

Answer:  {x = -1 , y = -4