Question

Please help me solve these equations. Very confusing.

Answer 1

Explanation:

1A (3,-2)

1B

By substitution

`4x - 3y = 18 \\ 2x + y = 4 \\ y = 4 - 2x \\ 4x - 3(4 - 2x) = 18 \\ 4x - 12 + 6x = 18 \\ 10x = 30 \\ x = 3 \\ y = 4 - 2(3) \\ y = 4 - 6 = - 2`

1C

By elimination

`(4x - 3y = 18) -2 * (2x + y = 4) \\( 4x - 3y = 18) - (4x + 2y = 8) \\ - 5y = 10 \\ y = - 2 \\ 4x - 3 * ( - 2) = 18 \\ 4x + 6 = 18 \\ 4x = 12 \\ x = 3`