The correct option is D −10x2+8xy+18y2−4x
Given: Sides of a rectangle are −6x2+9y2−5xy and x2−2x+9xy.
The perimeter of the rectangle = 2(length + breadth)
P=2[(−6x2+9y2−5xy)+(x2−2x+9xy)]
Grouping the like terms together,
P=2[(−6x2+x2)+9y2+(−5xy+9xy)−2x]
P=2(−5x2+4xy+9y2−2x)
P=−10x2+8xy+18y2−4x