Posted by **Christian** on Monday, May 21, 2007 at 10:41pm.

Replace each of the question marks with a value that will make the polynomial a perfect square trinomial.

1. 4x^2+12x+?

2. ?+90x+81

Could someone show me how to solve these?

Take the first:

factor out the 4

4x^2+12x+?

4( x^2 + 3x + ?)

take half the center term, and square it. half is 3/2, squared is 9/4

4( x^2 + 3x + 9/4)

Put the 4 back in...

4x^2 + 12x+9

(2x+3)(2x+3)

Second:

?+90x+81

Notice the last term is a perfect square, its square root is 9. Twice nine is eighteen.

Now to find the missing term, divide 90 by 18: five.

25x^2 + 90x + 81

(5x+9)(5x+9)

## Answer This Question

## Related Questions

- algebra 2 - find the value of c that makes each trinomial a perfect square. then...
- algebra - Question 8: What is the value of c such that: x2 + 14x + c, is a ...
- Algebra 1 - 1. What is the excluded value for the rational expression x^2 - 4/3x...
- Math - this question does not make sense to me. Add the proper constant to the ...
- math,help - Is this trinomial a perfect square x^2-6x+9 if the trinomial starts ...
- help...solving a polynomial....algebra - solve this please....help me....12x(...
- Math check - Complete the square: x^2 -12x. Which of the following is the ...
- Algebra Help - What is the value of c so that y = x² + 9x + c is a perfect ...
- Algebra - What is the value of c so that y = x² + 9x + c is a perfect square ...
- Algebra 1--Please, help me! - 1. Maria has 8 cups of a fruit punch that consists...

More Related Questions