Question

Factorise 9x2+y2+z2




-6xy+2yz-6zx. Hence find its value if x=1, y=2




and z=-1.

Answer 1

Answer:

Solution of Question -

Refer To The Attachment .

Plz mark it as brainliest .

Answer 2

Answer:

After factorization answer is (3x-y-z)².

If x=1, y=2 and z=-1 then value of the given expression is 4

Step-by-step explanation:

Given,

$9 {x}^{2} + {y}^{2} + {z}^{2} - 6xy + 2yz - 6zx$

$= {(3x)}^{2} + {y}^{2} + {z}^{2} - 2 \times 3x \times y + 2yz - 3 \times 2z \times x$

We know,

${a}^{2} + {b}^{2} + {c}^{2} + 2ab + 2bc + 2ca = {(a + b + c)}^{2}$

So,

${(3x)}^{2} + {y}^{2} + {z}^{2} - 2 \times 3x \times y + 2yz - 3 \times 2z \times x$

$= {(3x)}^{2} + {( - y)}^{2} + {( - z)}^{2} + 2 \times 3x \times( - y) + 2( - y)( - z) - 2\times ( - z) \times3 x$

$= {(3x - y - z)}^{2}$

It is also given that x=1, y=2 and z=-1.

So,

${(3x - y - z)}^{2} = {(3 \times 1 - 2 - ( - 1))}^{2} \\ = {(3 - 2 + 1)}^{2} \\ = {2}^{2} \\ = 4$

Know more about factorization,

https://brainly.in/question/1442807

https://brainly.in/question/609553

#SPJ2