Expand each of the following, using suitable identities : $(-2 x+5 y-3 z)^{2}$
Expand each of the following, using suitable identities : $(-2 x+5 y-3 z)^{2}$
$(-2 x+5 y-3 z)^{2}$
Using $(x+y+z)^{2}=x^{2}+y^{2}+z^{2}+2 x y+2 y z+2 z x,$ we have
$(-2 x+5 y-3 z)^{2}=(-2 x)^{2}+(5 y)^{2}+(-3 z)^{2}+2(-2 x)(5 y)+2(5 y)(-3 z)+2(-3 z)(-2 x)$
$\quad=4 x^{2}+25 y^{2}+9 z^{2}+[-20 x y]+[-30 y z]+[12 z x]$
$=4 x^{2}+25 y^{2}+9 z^{2}-20 x y-30 y z+12 z x$
Similar Questions
Find the value of the polynomial $5x -4x^2+ 3$ at $x = -\,1$.
Find the value of the polynomial $5x -4x^2+ 3$ at $x = -\,1$.
Verify : $x^{3}+y^{3}=(x+y)\left(x^{2}-x y+y^{2}\right)$
Verify : $x^{3}+y^{3}=(x+y)\left(x^{2}-x y+y^{2}\right)$
Expand each of the following, using suitable identities : $(2 x-y+z)^{2}$
Expand each of the following, using suitable identities : $(2 x-y+z)^{2}$
Factorise : $2 y^{3}+y^{2}-2 y-1$
Factorise : $2 y^{3}+y^{2}-2 y-1$
Find the zero of the polynomial : $p(x)=a x,\,\, a \neq 0$
Find the zero of the polynomial : $p(x)=a x,\,\, a \neq 0$