Question

For what value of m X^2 - 2mx + 7m - 12 = 0 have equal roots?

Answer 1

for roots to be equal the discriminant (d) = 0
b^2 - 4× a×c = 0
b = -2m
a = 1
c = 7m + 12
so putting the values
(-2m)^2 - 4 × 1× 7m -12
4m^2 - 28m +48 = 0
m^2 - 7m + 12 =0
m = 3 and m= 4