Respuesta :
You can plug -x - 1 for y in the first equation
2x - (-x - 1) = 10
2x + x + 1 = 10
Combine
3x = 9
Divide
x = 3
Plug 3 for x in any equation ( I'll use th second equation )
y = - (3) - 1
y = - 3 - 1 = -4
x = 3 ; y = -4
(3, -4)
2x - (-x - 1) = 10
2x + x + 1 = 10
Combine
3x = 9
Divide
x = 3
Plug 3 for x in any equation ( I'll use th second equation )
y = - (3) - 1
y = - 3 - 1 = -4
x = 3 ; y = -4
(3, -4)
2x - y = 10 .............(a)
y = -x - 1 ...........(b)
Substitute y = - x - 1 into equation (a)
2x - y = 10
2x - (-x - 1) = 10
2x + x + 1 = 10
3x + 1 = 10
3x = 10 - 1
3x = 9
x = 9/3 = 3. x = 3
Recall, y = -x - 1 = -3 - 1 = -4
Hence solution (x, y) = (3, -4)
y = -x - 1 ...........(b)
Substitute y = - x - 1 into equation (a)
2x - y = 10
2x - (-x - 1) = 10
2x + x + 1 = 10
3x + 1 = 10
3x = 10 - 1
3x = 9
x = 9/3 = 3. x = 3
Recall, y = -x - 1 = -3 - 1 = -4
Hence solution (x, y) = (3, -4)