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

a. 1/4B. 1/2C. 1D. 4

User Azuvector
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1 Answer

6 votes

x²+x given, we have to make it a perfect square.

To make it a perfect square first we have to check the x term. We have to check co-efficient of x. Here only x given, that means there is 1 with it. As x means 1*x which is also x. So, co-efficient of x is 1 here.

We will have to divide co-efficient of x by 2 and have to add the square with the expression to make it a perfect square.

As co-efficient of x is 1, so 1 divided by 2 is 1/2.

We are adding the square of 1/2 with the expression.

x²+x+(1/2)²

We know that (a+b)² = a²+2ab+b²

So here x²+2×(x)×(1/2)+(1/2)² = (x+1/2)², as 2×(x)×(1/2) = x

So by adding (1/2)² with it, we are getting a perfect square here.

(1/2)² =1/4

So, we have to add 1/4 with this expression to make it a perfect square.

User Emilio
by
6.5k points
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