Question

-2X² + 7x - 8 = 0????????????????????

Answer 1

-2x^2 +7x -8=0 *(-1)
2x^2 -7x +8=0
Delta=b^2 -4ac=(-7)^2 -4*2*8=49-64=-15

x1=-b+(-15)^(1/2) /2a=(7+i(15)^(1/2))/4
x2=(7-i(15)^(1/2))/4