5m2 – 2m = 2


(iv) 5m2 – 2m = 2

Sol. 5m2 – 2m = 2
∴  5m2 – 2m – 2 = 0
Comparing with ax2 + bx + c = 0 we have a = 5, b = – 2, c = – 2
b2 – 4ac = (– 2)2 – 4 (5) (– 2)
= 4 + 40
= 44
By Formula method,
m
=
-  b ± √(b2 – 4ac)




2a







∴ m
=
-(-2) ± √44




2(5)







∴ m
=
2 ± √44




10







∴ m
=
2±2√11




10







∴ m
=
2(1±√11)




10







∴ m
=
1 ± √11




5







∴ m
=
1 + √11
or
1 - √11


5

5