If your good at math and can do some one of my problems lmk but if not dont say yes or no just dont comment at all

Which property was used to simplify the expression? 3c+9 +4c=3c+4c+9

The base of a solid right pyramid is a square with an edge length of n units. the height of the pyramid is n - 1 units. sia (n-1 n

Aley is at the store buying some supplies for an art project. she decides to buy some colored pencils for $3.95 and a drawing tablet. the total cost of the supplies before sales tax is $6.94. what is the cost of the drawing tablet? $10.89 $2.99 $1.76 $3.01