Which value must be added to the expression x2 – 3x to make it a perfect-square trinomial?

9/4 should be added.

step-by-step explanation:

the given expression is x² - 3x and we have to tell which value must be added to the expression to make it a perfect square trinomial.

that means we have to convert the expression in the form of

(a - b)² = a² + b²- 2ab

here a = x

and -2ab = -3x

⇒ 2bx = 3x

⇒ b = 3/2

⇒ b² = (3/2)²

now the expression will be

therefore in the given expression (3/2)² = 9/4 should be added to make the expression a perfect square.

a perfect square trinomial can be written by formula

.

consider the expression . here

and you have to find

first, rewrite .

this means that . add and subtract from the given expression :

or

.

answer: must be added .

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