the sum of two trinomials is 7x squared - 5x + 4. If one of the trinomials is 3x squared + 2x - 1, then what is the other trinomial?

4x^2 - 7x + 5.

Step-by-step explanation:

Just subtract:

7x^2 - 5x + 4 - (3x^2 + 2x - 1) (Note we need the parentheses around the second triniomial).

= 7x^2 - 5x + 4 - 3x^2 - 2x + 1 Now subtract like terms:

= 4x^2 - 7x + 5.