A=x∈N:x2-5x-14=0হলে A=?
A=x∈N:x2-5x-14=0হলে A=? Correct Answer {7}
x2 - 5x - 14 = 0 x2 - 7x + 2x -14 = 0 x(x-7) + 2(x-7) = 0 (x-7)(x+2) = 0 x-7 = 0 or, x+2 = 0 x=7 x=-2 So, A = {7,-2}A=x∈N:x2-5x-14=0হলে A=? Correct Answer {7}
x2 - 5x - 14 = 0 x2 - 7x + 2x -14 = 0 x(x-7) + 2(x-7) = 0 (x-7)(x+2) = 0 x-7 = 0 or, x+2 = 0 x=7 x=-2 So, A = {7,-2}