Answer:
6y^2-7y-3
Step-by-step explanation:
(-7-10y+6y^2)+(4+3y)
-7-10y+6y^2+4+3y (Plus before brackets means the numbers stays the same)
6y^2+3y-10y+4-7 (Arrange them)
6y^2-7y-3 (Do the maths)