Prove that a positive integer is divisible by 3 if and only if the sum of digits is divisible by 3. be sure to prove it forward and backwards. as in prove knowing an integer is divisible by 3 and find that the sum of its digits is then divisible by 3. then, assume the sum of its digits is divisible by 3 and prove that the integer is then divisible by 3. if you cannot prove both ways, do not try and solve this problem.

marco saved more.   he saved $35 more.

step-by-step explanation:

1+2+3+4+5+6+7+8+9+10 = 55

2*10 = 20

55-20 = 35

81 seats

step-by-step explanation:

if you multiply 0.65 times 125 then you get 81.5 seats. well since you can't have half of a seat you have to round down and get 81 seats in the no children zones. that leave 44 seats outside of the no children zone.

answer: the two figures are congruent.

step-by-step explanation: they're congruent because figure efgh is reflected across the x and y axis but it was also rotated.

hope it !

step-by-step explanation:

b and c