Question

(D2+6d+9)+(d3-6d+9)

Answer 1

Collect like terms:

(8d+9) +(-3d+9)

Remove paranthesis:

8d+9-3d+9

Answer:

5d+18

Answer 2

Answer:5d+18

Step-by-step explanation:

(8d+9)+(-3d+9)

8d+9+-3d+9

8d-3d=5d

9+9=18

5d+18