Question

What value of c makes the expression y^2 -9y + c a perfect trunk mail square?

Answer 1

well.. break the middle term in the first step..
And divide it with 2

( since (a+b)^2 = (a)^2 + 2ab + b^2) ( Where a is first term and B is second)

so. to get ab we need to divide that term with 2

We get ab = (-9/2)y

Since in the given equation a = y

So, plugging in a as y in ab = (-9/2)y we get

(y) (b) = (-9/2)y

Now divide both sides of equation with y
=>
b = -9/2


Hence value of c = b = -9/2..


Did you get it?