Question

factorise a square b square c square minus 9 x square

Answer 1

${a}^{2} {b}^{2} {c }^{2} - 9 {x}^{2}$
$= {(abc)}^{2} - {(3x) }^{2}$
=(abc-3x)(abc+3x)

Answer 2

using the identity
${a}^{2} - {b}^{2} = (a + b)(a - b)$
we get
${a}^{2} {b}^{2} {c}^{2} - 9 {x}^{2} = (abc - 3x)(abc + 3x)$
Hope this helps