Question

Find the L.C.M. and H.C.F. of $2x^2-6x,x^2+9-6xand{x}^2-x-6$

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

To find the L.C.M. and H.C.F., we need to first resolve each expression into factors.
$2x^2-6x=2x(x-3)x^2+9-6x=x^2-2\times x\times 3+3^2$
$=(x-3{)}^2$
$x^2-x-6=x^2-3x+2x-6$
$=x(x-3)+2(x-3)$
$=(x-3)(x+2)$
$L.C.M.=2x(x-3{)}^2(x+2)$
$H.C.F.=(x-3)$