What value for c will make the expression a perfect square trinomial? x² – 7x + c
-(49/4), -(7/2), (7/2), (49/4)

Solution:

The standard form of a perfect square trinomial is

(x - a)² = x² - 2ax + a²

x² - 7x + c [Given]

By comparing it with the standard form

- 7x = - 2ax -------->(1)

c = a²-------->(2)

Solving the equations separately for a and x we get, 

- 7x = - 2ax

a = 7/2

c =  a² = (7/2)²

Here

(x - (7/2))² = x² - 7x + (49/4)

Therefore, the value of c is 49/4

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What value for c will make the expression a perfect square trinomial? x² – 7x + c
-(49/4), -(7/2), (7/2), (49/4)

Summary:

The value of c which makes the expression x² – 7x + c a perfect square trinomial is 49/4