X2 + y2 = (x + y) 2 + P = (X-Y) 2 + Q, then p=______ ，Q=______ ．

X2 + y2 = (x + y) 2 + P = (X-Y) 2 + Q, then p=______ ，Q=______ ．

X2 + y2 = (x + y) 2-2xy = (X-Y) 2 + 2XY, so the answer is - 2XY, 2XY

Wait for another line! X + 1 / x + 2 + X + 6 / x + 7 = x + 2 / x + 3 + X + 5 / x + 6
There is such an expansion problem in the exercise
x+1/x+2+x+6/x+7=x+2/x+3+x+5/x+6
Open the answer to see only - 9 / 2
But I want to know

X + 1 / x + 2 + X + 6 / x + 7 = x + 2 / x + 3 + X + 5 / x + 6, the original formula = x + 2 / x + 2 - 1 / x + 2 + X + 7 / x + 7 - 1 / x + 7 = x + 3 / x + 3 - 1 / x + 3 + X + 6 / x + 6 - 1 / x + 6

It is known that the trilateral equation of triangle ABC is ab: 5x - Y - 12 = 0, BC: X
It is known that the trilateral equation of triangle ABC is ab: 5x-y-12 = 0, BC: x + 3Y + 12 = 0, CA: x-5y + 12 = 0. Find the linear equation of the size of angle A and the height of side BC
BC：X+3Y+4=0

Slope of two straight lines AC and ab 1 / 5,5. Angle formula
|tanA|=|（5-1/5）/（1+5*1/5）|=12/5
The drawing shows that ∠ A is an acute angle, a = actan (12 / 5)
The second question is to solve the coordinate a of the intersection of AC and AB, where a (3,3), the height is perpendicular to BC, and the slope = - 1 / (- 3)
High equation Y-3 = 1 / 3 (x-3)