How to factorize this #(16-x^2)(4-y)^2-(4-x)^2(16-y^2)#?
1 Answer
Jun 1, 2018
Explanation:
#16-x^2" and "16-y^2" are "color(blue)"difference of squares"#
#•color(white)(x)a^2-b^2=(a-b)(a+b)#
#16-x^2=(4-x)(4+x)#
#16-y^2=(4-y)(4+y)#
#"we can now write the expression as"#
#(4-x)(4+x)(4-y)^2-(4-x)^2(4-y)(4+y)#
#"take out a "color(blue)"common factor "(4-x)(4-y)#
#=(4-x)(4-y)[(4+x)(4-y)-(4-x)(4+y)]#
#"expand the factors inside the square bracket"#
#(16-4y+4x-xy-(16+4y-4x-xy))#
#=(cancel(16)-4y+4xcancel(-xy)cancel(-16)-4y+4xcancel(+xy))#
#=(8x-8y)=8(x-y)#
#"putting it all together gives"#
#8(4-x)(4-y)(x-y)#