Help Needed With Math homework!

Hw Help, To Prove Him WRONG!?
Before you say anything negative, I'm not lazy, Im just trying to prove my older brother that he cant do math for even for his life. we both did this and we both have different answer. So Whose Right?
The Solution set for the equation x^2 -5x=6 is . . .
1. {1,-6}
2. {2,-3}
3. {-1,6}
4. {-2,3}

Solve for x: x^2+2x-24=0

Solve for x: x^2+3x-40=0

Solve for x: x^2+3x-28=0

Solve: (x-3)(x+3)=6x-14

x^2 - 5x - 6 = 0
(x - 6)(x + 1) = 0

x = 6
x = -1

3. {-1,6}

Solve for x: x^2+2x-24=0

(x + 6)(x - 4) = 0
x = -6
x = 4

Solve for x: x^2+3x-40=0

(x + 8)(x - 5) = 0
x = -8
x = 5

Solve for x: x^2+3x-28=0

(x + 7)(x - 4) = 0
x = -7
x = 4

Solve: (x-3)(x+3)=6x-14
x^2 - 9 = 6x - 14
x^2 - 6x + 5 = 0
(x - 5)(x - 1) = 0
x = 5
x = 1

Hope this Helps!

Before you say anything negative, I'm not lazy, Im just trying to prove my older brother that he cant do math for even for his life. we both did this and we both have different answer. So Whose Right?
The Solution set for the equation x^2 -5x=6 is . . .
1. {1,-6}
2. {2,-3}
3. {-1,6}
4. {-2,3}

JUST DOING THIS ONE SINCE YOU CAN FIGURE OUT HOW TO SOLVE THE OTHER ONES BY LOOKING AT THIS ONE!!

x^(2) - 5x = 6

Subtract 6 to both sides of the equation.

x^(2) - 5x - 6 = 0

Factor.

[x - 6] * [x + 1] = 0

Set each factor equal to zero and solve for x.

x = - 1, x = 6

{-1, 6} ---------------> ANSWER is choice 3

x^2 - 5x + (5/2)^2 = 6 + (5/2)^2 by completing the square
(x-5/2)^2 = 49/4 = (7/2)^2
x = 5/2 +/- 7/2
x = 6
x = -1
{3}

x^2 -5x=6
(x-2)(x-3) = 0
x = 2, 3

x^2+2x-24=0
(x+6)(x-4) = 0
x = -6, 4

x^2+3x-40=0
(x+8)(x-5) = 0
x = -8, 5

x^2+3x-28=0
(x+7)(x-4) = 0
x = -7, 4

(x-3)(x+3)=6x-14
x² - 6x + 5 = 0
(x-1)(x-5) = 0
x = 1, 5