Question

Find "m"so that quadratic equation mx(x-7)+49=0, has 2equal roots.

Answer 1

The given quadratic equation is mx (x-7)+49=0

mx2-7mx+49=0

a = m, b = -7m, c = 49

It is given that the roots of this equation are equal.

D = b2 - 4ac=0

(-7m)2 - 4(m)(49)=0

49m2 - 4(m)(49)=0

49m(m-4)=0

49m=0 or m - 4 = 0

m = 0 or m=4

For m = 0 equation will not be quadratic hence m = 4