3x^2 - 5x + 12
5x^2 + x - 11

Answer:
8x²+5x+1
Step-by-step explanation:
3x²-5x+12
5x²+ x - 11
________
3x²+5x²= 8x²
}
5x+x =5x
}
12-11 =1
=
8x²+5x+1