Q4 D of 42 Page 136

Let’s find the L.C.M. of the following algebraic expressions:

ab4-8ab, a2b4 + 8a2b, ab4-4ab2


factors of ab4-8ab

=ab(b3-8)


=ab(b-2)(b2 + 2b + 4)


Factors of a2b4 + 8a2b


=a2b(b3 + 8)


= a2b(b + 2)( b2-2b + 4)


Factors of ab4-4ab2


=ab2(b2-4)


= ab2(b + 2)(b-2)


LCM is the lowest common multiple, which is the product of all the common factors taken once and the remaining factors as it is.


∴ the LCM of ab4-8ab, a2b4 + 8a2b, ab4-4ab2 is


a2b2(b + 2)(b-2)(b2-2b + 4)(b2 + 2b + 4)


= a2b2(b3 + 8) (b3-8)


More from this chapter

All 42 →
4

Let’s find the L.C.M. of the following algebraic expressions:

(x2y2-x2);(xy2-2xy + x)


 4

Let’s find the L.C.M. of the following algebraic expressions:

(p + q) (p + r), (q + r) (r + p), (r + p) (p + q)


 4 E

Let’s find the L.C.M. of the following algebraic expressions:

x4 + x2y2 + y4, x3y + y4, (x2-xy)3


 4 F

Let’s find the L.C.M. of the following algebraic expressions:

p2 + 2p, 2p4 + 3p3-2p2, 2p3-3p2-14p