Answer:
The answer is B
Step-by-step explanation:
(−3x2)(5x−4x2−6)
=(−3x2)(5x+−4x2+−6)
=(−3x2)(5x)+(−3x2)(−4x2)+(−3x2)(−6)
=−15x3+12x4+18x2
=12x4−15x3+18x2
sum of angles in a quadrilateral is 360
3x-15 +3x+15+y+30+D=360
hope that explanation helps