(2x²<span> + 3x - 4) + (8 - 3x) + (-5x</span>²<span> + 2)
= </span> 2x² + 3x - 4 + 8 - 3x - 5x² + 2
= -3x² + 6
= 3(-x² + 2)
For line B to AC: y - 6 = (1/3)(x - 4); y - 6 = (x/3) - (4/3); 3y - 18 = x - 4, so 3y - x = 14
For line A to BC: y - 6 = (-1)(x - 0); y - 6 = -x, so y + x = 6
Since these lines intersect at one point (the orthocenter), we can use simultaneous equations to solve for x and/or y:
(3y - x = 14) + (y + x = 6) => 4y = 20, y = +5; Substitute this into y + x = 6: 5 + x = 6, x = +1
<span>So the orthocenter is at coordinates (1,5), and the slopes of all three orthocenter lines are above.</span>
x = 130 is your answer
130 - 20 = 110
Since line E and F are parallel and are straight lines, we know both angles will add up to 180°
110 + 70 = 180