Question

find the value for b that will make the trinomial 4x^2+bx+81 a perfect square trinomial. FACTOR the resulting:

Answer 1

Answer:

Explanation:

Given the below trinomial;

$4x^2+bx+81$

We're asked to determine the value of b to make the above trinomial a perfect square.

To solve the above, note that perfect square trinomials are generally written in the below form;

$(ax\pm b)^2=(ax)^2\pm2axb+b^2$

Let's rewrite the given trinomial in the above form, we'll have;

$4x^2+bx+81=(2x)^2+2bx+9^2$

If we compare both expressions, we can observe the below;

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