Given that the line L: x-2y-5 = 0 and the circle C: x + y = 50, find (1) the coordinates of intersection a and B, and (2) the area of △ AOB Such as the title, to complete the thinking and process

Given that the line L: x-2y-5 = 0 and the circle C: x + y = 50, find (1) the coordinates of intersection a and B, and (2) the area of △ AOB Such as the title, to complete the thinking and process


The best answer is 1, x = 2Y + 5 into 5Y + 20Y + 25 = 50, y + 4y-5 = 0, y = 1, y = - 5, x = 2Y + 5, so a (7,1), B (- 5, - 5) 2, ab = √ [(7 + 5) + (1 + 5)] = 6 √ 5, the distance from O to L = | 0-0-5 | / √ (1 + 2) = √ 5, the bottom edge is 6 √ 5, the height is 5, so the area is 15



The equation of the circle with the intersection of the straight line x + 3y-7 = 0 and the known circle X & sup2; + Y & sup2; + 2x-2y-3 = 0 and the sum of the four intercepts on the two coordinate axes is - 8 is obtained


X + 3y-7 = 0 and the known circle X & sup2; + Y & sup2; + 2x-2y-3 = 0 intersection (1,2) (- 2,3) assumption: the equation of the circle (x-a) ^ 2 + (y-b) ^ 2 = R ^ 2x = 0, y ^ 2-2by + A ^ 2 + B ^ 2-r ^ 2 = 0, Y axis intercept Y1 + y2 = 2by = 0, x ^ 2-2ax + A ^ 2 + B ^ 2-r ^ 2 = 0, X axis intercept X1 + x2 = 2A, so: 2A + 2B = - 8, (1-A) ^ 2 + (2-B)



{(x+2y)(x-2y)+[2(x-y)]²}÷6x=?


The original formula = (X & # 178; - 4Y & # 178; + 4x & # 178; - 8xy + 4Y & # 178;) / 6x
=(5x²-8xy)÷6x
=(5x-8y)/6