4. Use mathematical induction to prove the truth of each of the following assertions for all n 2 1. n + (n + 1)+(n + 2) is divisible by 9 k+12'+(k+2d") k+343-Z k+243+2 k+123+2 d. 8"-3" is divisible by 5 8*8*-3*3*=(5+3 *8*-3*3*=5*8*+3*(8*-3* ) n'+5n is divisible by 6 k+1d'+5 k+1)=k'+3k?+3k+1+5k+5=k'+3k'+8k+6=(q+1 +3k +3k