Question

The HCF of two expression is x and their LCM is $x^3-9x$ If one of the expressions is $x^2+3x$, then find the other expression.

• A. $x^2-3x$
• B. $x^2+6x$
• C. $x^2-3$
• D. $x^2+3x$

Answer 1

The correct option is A $x^2-3x$

HCF $HCF=x,LCM=x^3-9x$
Given expression $=x^2+3x=x(x+3)$

$\therefore$ Other expression $=\frac{HCF\times LCM}{Givenexpression}=\frac{x\times x\times (x+3)\times (x-3)}{x\times (x+3)}=x(x-3)=x^2-3x$