12. S=4pir^2 S=4pi(3x+2)^2 Use square of sum (a+b)^2=a^2+2ab+b^2 4pi((3x)^2+2*3x*2+2^2) 2. Use multiplication distributive property (xy)^a=x^ay^a 4pi(3^2x^2+2*3x*2+2^2) Simplify 3^2 to 9 4pi(9x^2+2*3x*2+2^2) Simplify 2^2 to 4 4pi(9x^2+2*3x*2+4) Simplify 2*3x*2 to 12x 4pi(9x^2+12x+4) Distribute 36pix^2+48pix+16pi