Answer:
u² + 2u + <u>1</u>
Step-by-step explanation:
In the question it's asking to find the the number in the blank to make the expression a perfect square.
Let the number in the blank be 'x'.
To guess 'x' , use the algebraic identity :-
While matching the expression with identity , the expression will look like this :- <em>u² + 2ux + </em><u><em>x²</em></u>
In the expression given in the question , it's "2u" but after matching the expression with identity , it is found to be "2ux".
⇒ x = 1 (∵ If x will be 1 , then 2ux = 2×u×1 = 2u)
⇒ <u>x²</u> = <u>1</u>
∴ The number in the blank is 1.
