(1)
(2x+7)(x-5) = -43 + jx simplify the left side
2x^2 + 7x -10x - 35 = -43 + jx rearrange as
2x^2 + (7 - j)x + 8 = 0
If this has one real solution.....then the discriminant must = 0
So
(7 -j)^2 - 4 (2)(8) =0
49 - 14j + j^2 - 64 = 0 rearrange as
j^2 -14j - 15 = 0 factor as
(j -15) ( j + 1) = 0
Set both facotrs to 0 and solve for j and we get that
j =15 and j = -1
So....we will have one real solution when j = -1 or j =15
See the graph here to confirm this : https://www.desmos.com/calculator/dw6lnjpnm7
