Short Answer: Combine like terms
Remark
Just from what I see here, remove the brackets first and combine like terms second.
Discussion
8 - 2x + 4 The like therms are 8 and 4 First step
12 - 2x That's the answer. Don't go any further. 2nd and last step
Answer:
90 degree rotation in the clockwise direction.
Step-by-step explanation:
Point A transforms to A'
- that is x coordinate: 2 ---> 3
and y coordinate 3 ---> -2
So the rotation is clockwise from Quadrant1 to Quadrant 4.
The slope of OA = 3/2 and the slope of OA' = -2/3.
The product of these slopes = 3/2 * -2/3 = -1 so the lines are perpendicular - that is the line has passed through an angle of 90 degrees.
A similar result occurs if we consider points B, C and D.
Steps 4 and 5 are being used to get the equation in step 6.
Steps 5 and 7 are being used to get the equation in step 8.
Steps 8 and 6 are being used to get the equation in step 9.
In step 14, "similar argument" means to draw segment BD and follow the same logic in steps 3-12.
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>