Answer :

Answer:

Step-by-step explanation: 3x^2-4x+15

1. (5x^2+3)-(2x^2+4x-12)

2. (5x^2+3)-1(2x^2+4x-12)

3. 5x^2+3-2x^2-4x+12

4. 3x^2-4x+15