Factorise 9 X square + Y square + Z square - 6 X Y + 2 Y Z - 6 x z hence find its value when X is equals to 1 by equal to 2 and Z = 2 - 1

a) Factor 9x² + y² + z² - 6xy + 2yz - 6xz

This looks a lot like

(x+y+z)² = x² + y² + z²+ 2xy + 2yz + 2xz

except instead of x there's (-3x).   So this must be

(-3x+y+z)² = (-3x)² + y² + z² + 2((-3x)y + (-3x)z + yz)

= 9x² + y² + z² - 6xy + 2yz - 6xz

Looks good.

(-3x+y+z)²

Since it's a square we could also negate the inside and write this (3x-y-z)²

b) I'll guess that says we want to evaluate this when x=1, y=2, z= -1

(-3(1) + 2 -1)² = (-2)² = 4

4

x = 25/2304

step-by-step explanation:

c. 27 units.

step-by-step explanation:

we are told that in circle a, ∠bae ≅ ∠dae.

we can see from our given diagram that in and ;

, as these are radii of our given circle.

therefore, by sas congruence postulate.

hence, side be will be equal to side de as corresponding parts of congruent triangles are congruent. so we can set an equation to find the value of x as:

now let us substitute x=17 in the expression for the length of be.

therefore, length of be will be 27 units and option c is the correct choice.