Question

factorise the following
25x2+16y2+4z2-40xy+16yz-20yz​

Answer 1

Step-by-step explanation:

25x

2

+16y

2

+4z

2

−40xy+16yz−20xz

= (−5x)

2

+(4y)

2

+(2z)

2

+2(−5x)(4y)+2(4y)(2z)+2(−5x)(2z)

Suitable identities is (x+y+z)

3

=x

3

+y

3

+z

3

+2xy+2yz+2xz

Therefore, (−5x)

2

+(4y)

2

+(2z)

2

+2(−5x)(4y)+2(4y)(2z)+2(−5x)(2z)

= (−5x+4y+2z)

2