Question

Please help me, tomorrow is the deadline.

Answer 1

I only know the substitutional method so I am going to give you the answers.

1. (remember I am only using the substitutional method, I am doing the method wrong...)

x + y = 10, 3x - y = 2, 5(3x-y) = 5(2), 15x - 5y = 10, 15x -5y = x + y, 14x = 6y, x = 3/7 y , 3/7 y + y = 10, 10/7y = 10, 10 y = 70, y = 7, 14x = 42. x =3

y = 7, x = 3

2. What I know:

x + y = 6

x + 2x = 6

3x = 6

x = 2, y =4

3. I am using a video to help me remember.

x = 2y + 3     2x + 3y = -3.

-3 = 2y - x     -3 = 3y + 2x

0 = - y + 3x,     y = 3x

x = 2(3x) + 3,   x = 6x + 3

-5x = 3,            x = -3/5

y = 3(-3/5)

y = -9/5, x = -3/5