Question

PLEAS ANSWER ME I BACK TO A FOLLOW AN THANKS

Answer 1

Answer:

Step-by-step explanation:

(a+b+c)^2 = a^2 + b^2 +c^2 + 2ab +2bc+2ac

(a+b+c)^2 = -2x^2 + 9y^2 + z^2 + 2×-2x×9y + 2×9y×z + 2×-2x×z

(-2x+9y+z)^2