Q1 of 108 Page 46

Find the lowest common multiple of the following expressions:

x2 – 3x + 2 and x4 + x3 – 6x2


Let u(x) = x2 – 3x + 2

On factorizing the above equation,


Sum = -3


Product = 2


Therefore the two numbers satisfying the above conditions are -2 and -1.


u(x) = x2 – x – 2x – 2


u(x) = x(x – 1) - 2(x – 1)


u(x) = (x – 2) (x – 1)


Let v(x) = x4 + x3 – 6x2


= x2(x2 + x – 6)


Solving the quadratic part,


x2 + x – 6


x2 + 3x – 2x – 6


x(x + 3) – 2(x + 3)


(x – 2) (x + 3)


Therefore v (x) = x2 (x – 2) (x + 3)


By comparing u(x) and v(x),


LCM = x2 (x – 2) (x + 3) (x – 1)


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