# algebra

posted by .

Use the discriminant to find out whether this quadratic polynomial can be factored. Factor the polynomial if it is not prime. This polnomial is prime, so I cannot factor it. I just need help with the discriminant part. Thaks in advance for your help.

4x^2-27x+45

• algebra -

The discriminant is b^2 - 4 ac = 729 -720 = 9. Since the square root of that is an integer (3), the polynomial can be factored.

The roots are (1/8)[27 +/-3] = 30/8 and 3

4x^2-27x+45 = (x-3)(4x- 15) are the factors

## Similar Questions

1. ### algebra 2

Factor completely with respect to the integers. 1. 9x^2 - 4 2. x^3 + 64 3. 200x^2 - 50 4. 8x^3 - 64 5. x^3 + x^2 + x + 1 6. x^3 - 2x^2 + 4x - 8 7. 2x^3 + 4x^2 + 4x + 8 8. 2x^3 + 3x^2 -32x - 48 9. 7x^3 + 14x^2 + 7x 10. 6x^3 - 18x^2 …

Could you please check these answers thanks. Directions: Factor each polynomial. If the polynomial cannot be factored, write prime. 1. a^2-16b Answer: (a-16)(a+16) 2. m^2+8m+16 Answer: (m+8)^2 3. 3a^2b+6ab+9ab^2 Answer: Prime 4. 2r^2+3r+1 …
3. ### Algebra

Explain why x^2 +5x + 8 is prime(not factorable) How do you know?
4. ### Algebra

Explain why x^2 + 5x + 8 is prime (not factorable). How do you know?

Factor completely. If the polynomial cannot be factored say it is prime. 1) 15x^3 + 19x^2 + 6x A) (3x^2 +2)(5x+3) B) x(3x+2)(5x+3) C) x^2(3x+2)(5x+3) D) x(5x+2)(3x+3) E) Prime I chose E) Prime. 2) 2x^2 - 14x - 6x + 42 A) 2(x+7)(x+3) …
6. ### math

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime. 15b^2-24bf
7. ### Algebra

How do you factor ax^2+bx+c? I'm so confused. I remember my teacher saying to use the discriminant b^2-4ac but when I do find the answer what do I next?
8. ### MATH 101

Factor completely. Be sure to factor out the greatest common factor first if it is other than 1. (If the polynomial is prime, enter PRIME.) 56a^2+39ab-27b^2
9. ### algebra--1 question

Suppose you divide a polynomial by a binomial. How do you know if the binomial is a factor of the polynomial?
10. ### Math

Find the discriminant for the quadratic equation f(x) = 5x^2 - 2x + 7 and describe the nature of the roots. discriminant is 144, one real root discriminant is -136, two complex roots <--?

More Similar Questions