72.5k views
21 votes
What polynomial should be subtracted from 3x^2+4x-1 to get the difference equal to 1

User Ahmad Mayo
by
7.4k points

1 Answer

5 votes

Answer: 3x^2+4x-2

=====================================================

Step-by-step explanation:

Assume the polynomial we want to find is in the form Ax^2+Bx+C

The goal is to find the values of A, B, and C.

We start with 3x^2+4x-1, then we subtract off Ax^2+Bx+C. Set this equal to 1 and we get:

(3x^2+4x-1) - (Ax^2+Bx+C) = 1

3x^2+4x-1 -Ax^2-Bx-C = 0x^2 + 0x + 1

(3x^2-Ax^2) + (4x-Bx) + (-1-C) = 0x^2 + 0x + 1

(3-A)x^2 + (4-B)x + (-1-C) = 0x^2 + 0x + 1

From here we equate the coefficients of the x^2 terms together and we see that 3-A = 0 which leads to A = 3.

Do the same for the x terms to get 4-B = 0 leading to B = 4

Finally, we have -1-C = 1 lead to C = -2

The polynomial Ax^2+Bx+C becomes 3x^2+4x-2

-------------------

Checking the answer:

(3x^2+4x-1) - (Ax^2+Bx+C)

(3x^2+4x-1) - (3x^2+4x-2)

3x^2+4x-1 - 3x^2-4x+2

(3x^2-3x^2) + (4x-4x) + (-1+2)

0x^2 + 0x + 1

0 + 0 + 1

1

We get a difference of 1, so the answer is confirmed.

User Thehme
by
7.9k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.