Question

find the valueofm if one root of the equation 2x2-8x-m = 0 is 5 / 2

Answer 1

Put x=5/2 in given eqn
2(5/2)2-8(5/2)-m=0
2×25/4-8×5/2-m=0
25/2-20-m=0
25-40-2m=0
-15-2m=0
m=-15/2 ans