Question

write the following in expanded form : (4x - 3y + z) ^2​

Answer 1

$\left(4x-3y+z\right)^2$

$=\left(4x+z-3y\right)\left(4x+z-3y\right)$

$=4x\cdot \:4x+4x\left(-3y\right)+4xz+\left(-3y\right)\cdot \:4x+\left(-3y\right)\left(-3y\right)+\left(-3y\right)z+z\cdot \:4x+z\left(-3y\right)+zz$

$=4\cdot \:4xx-4\cdot \:3xy+4xz-3\cdot \:4xy+3\cdot \:3yy-3yz+4xz-3yz+zz$

$=-24xy+8xz+16x^2+9y^2-6yz+z^2$