Answer:
21
Step-by-step explanation:
a,a+2,..
4(a+2)=29+3a
4a+8=29+3a
4a-3a=29-8
a=21
729
3 to the power of 2 means 3 * 3 which is 9. 3 to the power of 4 means 3 * 3 * 3 * 3 which is 81. Finally, 9 * 81 which gives you 729.
